CONCORDAT (Lat. concordatum, agreed upon, from con-, together, and cor, heart), a term originally denoting an agreement between ecclesiastical persons or secular persons, but later applied to a pact concluded between the ecclesiastical authority and the secular authority on ecclesiastical matters which concern both, and, more specially, to a pact concluded between the pope, as head of the Catholic Church, and a temporal sovereign for the regulation of ecclesiastical affairs in the territory of such sovereign. It is to concordats in this later sense that this article refers.
No one now questions the profound distinction that exists between the two powers, spiritual and temporal, between the church and the state. Yet these two societies are none the less in inevitable relation. The same men go to compose both; and the church, albeit pursuing a spiritual end, cannot dispense with the aid of temporal property, which in its nature depends on the organization of secular society. It follows of necessity that there are some matters which may be called "mixed," and which are the legitimate concern of the two powers, such as church property, places of worship, the appointment and the emoluments of ecclesiastical dignitaries, the temporal rights and privileges of the secular and regular clergy, the regulation of public worship, and the like. The existence of such mixed matters gives rise to inevitable conflicts of jurisdiction, which may lead, and sometimes have led, to civil war. It is, therefore, to the general interest that all these matters should be settled pacifically, by a common accord; and hence originated those conventions between the two powers which are known by the significant name of concordat, the official name being pactum concordatum or solemnis conventio. In theory these agreements may result from the spontaneous and pacific initiative of the contracting parties, but in reality their object has almost always been to terminate more or less acute conflicts and remedy more or less disturbed situations. It is for this reason that concordats always present a clearly marked character of mutual concession, each of the two powers renouncing certain of its claims in the interests of peace.
For the purposes of a concordat the state recognizes the official status of the church and of its ministers and tribunals; guarantees it certain privileges; and sometimes binds itself to secure for it subsidies representing compensation for past spoliations. The pope on his side grants the temporal sovereign certain rights, such as that of making or controlling the appointment of dignitaries; engages to proceed in harmony with the government in the creation of dioceses or parishes; and regularizes the situation produced by the usurpation of church property etc. The great advantage of concordats - indeed their principal utility - consists in transforming necessarily unequal unilateral claims into contractual obligations analogous to those which result from an international convention. Whatever the obligations of the state towards the ecclesiastical society may be in pure theory, in practice they become more precise and stable when they assume the nature of a bilateral convention by which the state engages itself with regard to a third party. And reciprocally, whatever may be the absolute rights of the ecclesiastical society over the appointment of its dignitaries, the administration of its property, and the government of its adherents, the exercise of these rights is limited and restricted by the stable engagements and concessions of the concordatory pact, which bind the head of the church with regard to the nations.
A concordat may assume divers forms, - historically, three. The most common in modern times is that of a diplomatic convention debated between the authorized mandatories of the high contracting parties and subsequently ratified by the latter; as, for example, the French concordat of 1801. Or, secondly, the concordat may result from two identical separate acts, one emanating from the pope and the other from the sovereign; this was the form of the first true concordat, that of Worms, in 1122. A third form was employed in the case of the concordat of 1516 between Leo X. and Francis I. of France; a papal bull published the concordat in the form of a concession by the pope, and it was afterwards accepted and published by the king as law of the country. The shades which distinguish these three forms are not without significance, but they in no way detract from the contractual character of concordats.
Since concordats are contracts they give rise to that special mutual obligation which results from every agreement freely entered into; for a contract is binding on both parties to it. Concordats are undoubtedly conventions of a particular nature. They may make certain concessions or privileges once given without any corresponding obligation; they constitute for a given country a special ecclesiastical law; and it is thus that writers have sometimes spoken of concordats as privileges. Again, it is quite certain that the spiritual matters upon which concordats bear do not concern the two powers in the same manner and in the same degree; and in this sense concordats are not perfectly equal agreements. Finally, they do not assume the contracting parties to be totally independent, i.e. regard is had to the existence of anterior rights or duties. But with these reservations it must unhesitatingly be said that concordats are bilateral or synallagmatic contracts, from which results an equal mutual obligation for the two parties, who enter into a juridical engagement towards each other. Latterly certain Catholics have questioned this equality of the concordatory obligation, and have aroused keen discussion. According to Maurice de Bonald (Deux questions sur le concordat de 1801, Geneva, 1871), who exaggerates the view of Cardinal Tarquini (Instit. juris publ. eccl., 1862 and 1868), concordats would be pure privileges granted by the pope; the pope would not be able to enter into agreements on spiritual matters or impose restraints upon the power of his successors; and consequently he would not bind himself in any juridical sense and would be able freely to revoke concordats, just as the author of a privilege can withdraw it at his pleasure. This exaggerated argument found a certain number of supporters, several of whom nevertheless sensibly weakened it. But the best canonists, from the Roman professor De Angelis (Prael. juris canon. i. 106) onwards, and all jurists, have victoriously refuted this theory, either by insisting on the principles common to all agreements or by citing the formal text of several concordats and papal acts, which are as explicit as possible. They have thus upheld the true contractual nature of concordats and the mutual juridical obligation which results from them.
The foregoing statements must not be taken to mean that concordats are in their nature perpetual, and that they cannot be broken or denounced. They have the perpetuity of conventions which contain no time limitation; but, like every human convention, they can be denounced, in the form in use for international treaties, and for good reasons, which are summed up in the exigencies of the general good of the country. Nevertheless, there is no example of a concordat having been denounced or broken by the popes, whereas several have been denounced or broken by the civil powers, sometimes in the least diplomatic manner, as in the case of the French concordat in 1905. The rupture of the concordat at once terminates the obligations which resulted from it on both sides; but it does not break off all relation between the church and the state, since the two societies continue to coexist on the same territory. To the situation defined by concordat, however, succeeds another situation, more or less uncertain and more or less strained, in which the two powers legislate separately on mixed matters, sometimes not without provoking conflicts.
We cannot describe in detail the objects of concordatory conventions. They bear upon very varied matters,  and we must confine ourselves here to a brief résumé. In the first place is the official recognition by the state of the Catholic religion and its ministers. Sometimes the Catholic religion is declared to be the state religion, and at least the free and public exercise of its worship is guaranteed. Several conventions guarantee the free communication of the bishops, clergy and laity with the Holy See; and this admits of the publication and execution of apostolic letters in matters spiritual. Others define those affairs of major importance which may be or must be referred to the Holy See by appeal, or the decision of which is reserved to the Holy See. On several occasions concordats have established a new division of dioceses, and provided that future erections or divisions should be made by a common accord. Analogous provisions have been made with regard to the territorial divisions within the dioceses; parishes have been recast, and the consent of the two authorities has been required for the establishment of new parishes. As regards candidates for ecclesiastical offices, the concordats concluded with Catholic nations regularly give the sovereign the right to nominate or present to bishoprics, often also to other inferior benefices, such as canonries, important parishes and abbeys; or at least the choice of the ecclesiastical authority is submitted to the approval of the civil power. In all cases canonical institution (which confers ecclesiastical jurisdiction) is reserved to the pope or the bishops. In countries where the head of the state is not a Catholic, the bishops are regularly elected by the chapters, but the civil power has the right to strike out objectionable names from the list of candidates which is previously submitted to it. Other conventions secure the exercise of the jurisdiction of the bishops in their diocese, and determine precisely their authority over seminaries and other ecclesiastical establishments of instruction and education, as well as over public schools, so far as concerns the teaching of religion. Certain concordats deal with the orders and congregations of monks and nuns with a view to subjecting them to a certain control while securing to them the legal exercise of their activities. Ecclesiastical immunities, such as reservation of the criminal cases of the clergy, exemption from military service and other privileges, are expressly maintained in a certain number of pacts. One of the most important subjects is that of church property. An agreement is come to as to the conditions on which pious foundations are able to be made; the measure in which church property shall contribute to the public expenses is indicated; and, in the 19th century, the position of those who have acquired confiscated church property is regularized. In exchange for this surrender by the church of its ancient property the state engages to contribute to the subsistence of the ministers of public worship, or at least of certain of them.
Scholars agree in associating the earliest concordats with the celebrated contest about investitures (q.v.), which so profoundly agitated Christian Europe in the 11th and 12th centuries. The first in date is that which was concluded for England with Henry I. in 1107 by the efforts of St Anselm. The convention of Sutri of 1111 between Pope Paschal II. and the emperor Henry V. having been rejected, negotiations were resumed by Pope Calixtus II. and ended in the concordat of Worms (1122), which was confirmed in 1177 by the convention between Alexander III. and the emperor Frederick I. In this concordat a distinction was made between spiritual investiture, by the ring and pastoral staff, and lay or feudal investiture, by the sceptre. The emperor renounced investiture by ring and staff, and permitted canonical elections; the pope on his part recognized the king's right to perform lay investiture and to assist at elections. Analogous to this convention was the concordat concluded between Nicholas IV. and the king of Portugal in 1289.
The lengthy discussions on ecclesiastical benefices in Germany ended finally in the concordat of Vienna, promulgated by Nicholas V. in 1448. Already at the council of Constance attempts had been made to reduce the excessive papal reservations and taxes in the matter of benefices, privileges which had been established under the Avignon popes and during the Great Schism; for example, Martin V. had had to make with the different nations special arrangements which were valid for five years only, and by which he renounced the revenues of vacant benefices. The council of Basel went further: it suppressed annates and all the benefice reservations which did not appear in the Corpus Juris. Eugenius IV. repudiated the Basel decrees, and the negotiations terminated in what was called the "concordat of the princes," which was accepted by Eugenius IV. on his death-bed (bulls of February 5 and 7, 1447). In February 1448 Nicholas V. concluded the arrangement, which took the name of the concordat of Vienna. This concordat, however, was not received as law of the Empire. In Germany the concessions made to the pope and the reservations maintained by him in the matter of taxes and benefices were deemed excessive, and the prolonged discontent which resulted was one of the causes of the success of the Lutheran Reformation.
In France the opposition to the papal exactions had been still more marked. In 1438 the Pragmatic Sanction of Bourges adopted and put into practice the Basel decrees, and in spite of the incessant protests of the Holy See the Pragmatic was observed throughout the 15th century, even after its nominal abolition by Louis XI. in 1461. The situation was modified by the concordat of Bologna, which was personally negotiated by Leo X. and Francis I. of France at Bologna in December 1515, inserted in the bull Primitiva (August 18, 1516), and promulgated as law of the realm in 1517, but not without rousing keen opposition. All bishoprics, abbeys and priories were in the royal nomination, the canonical institution belonging to the pope. The pope preserved the right to nominate to vacant benefices in curia and to certain benefices of the chapters, but all the others were in the nomination of the bishops or other inferior collators. However, the exercise of the pope's right of provision still left considerable scope for papal intervention, and the pope retained the annates.
In the 17th century we have only to mention the concordat between Urban VIII. and the emperor Ferdinand II. for Bohemia in 1640. In the 18th century concordats are numerous: there are two for Spain, in 1737 and 1753; two for the duchy of Milan, in 1757 and 1784; one for Poland, in 1736; five for Sardinia and Piedmont, in 1727, 1741, 1742, 1750 and 1770; and one for the kingdom of the Two Sicilies in 1741.
After the political and territorial upheavals which marked the end of the 18th century and the beginning of the 19th, all these concordats either fell to the ground or had to be recast. In the 19th century we find a long series of concordats, of which a good number are still in force. The first in date and importance is that of 1801, concluded for France between Napoleon, First Consul, and Pius VII. after laborious negotiations. Save in the provisions relating to ecclesiastical benefices, all the property of which had been confiscated, it reproduced the concordat of 1516. The pope condoned those who had acquired church property; and by way of compensation the government engaged to give the bishops and curés suitable salaries. The concordat was solemnly promulgated on Easter Day 1802, but the government had added to it unilateral provisions of Gallican tendencies, which were known as the Organic Articles. After having been the law of the Church of France for a century, it was denounced by the French government in 1905. It remains, however, partly in force for Belgium and Alsace-Lorraine, which formed part of French territory in 1801.
We conclude with a brief chronological survey of the concordats during the 19th century, some now abrogated or replaced, others maintained. It must be observed that the denunciation of a concordat by a nation does not necessarily entail the separation of the church and the state in that country or the rupture of diplomatic relations with Rome.
1803. For the Italian republic, between Napoleon and Pius VII., analogous to the French concordat; abrogated.
1813. It is impossible to designate as a concordat the concessions which were wrested by violence from Pius VII. when ill and in seclusion at Fontainebleau, and which he at once retracted.
1817. For Bavaria; still in force.
1817. New French concordat, in which Louis XVIII. endeavoured to revive the concordat of 1516; but it was not put to the vote in the chambers, and never came into force.
1817. For Piedmont, completed in 1836 and 1841; was suppressed, like all other Italian concordats, by the formation of the kingdom of Italy.
1818. For the Two Sicilies, completed in 1834; lasted until the invasion of the kingdom of Naples by Piedmont.
1821. For Prussia; still in force.
1821. For the Rhine provinces not incorporated in Prussia, with the special object of regulating episcopal elections; concerned Württemberg, Baden, Hesse, Saxony, Nassau, Frankfort, the Hanseatic towns, Oldenburg and Waldeck. This first concordat was immediately suspended, and was not ratified until 1827; it is partially maintained. It had to be replaced by new concordats concluded with Württemberg in 1857 and the grand-duchy of Baden in 1859; but these conventions, not having been ratified by those countries, never came into force.
1824. For the kingdom of Hanover; maintained.
1827. For Belgium and Holland; abandoned by a common accord.
1828 and 1845. For Switzerland, for the reorganization of the bishoprics of Basel and Soleure; in force.
1851. For Tuscany; lasted until the formation of the kingdom of Italy.
1851. For Spain, completed in 1859 and 1888; in force.
A convention on the religious orders was concluded in 1904, but had not received the assent of the Senate in 1908.
1855. For Austria; denounced in 1870. Several of its provisions are maintained by unilateral Austrian laws. The emperor of Austria continues to nominate to bishoprics by virtue of rights anterior to this concordat.
1857. For Portugal, completed in 1886 for the Portuguese possessions in the Indies; in force.
1886. For Montenegro; in force.
The numerous concordats concluded towards the middle of the 19th century with several of the South American republics either have not come into force or have been denounced and replaced by a more or less pacific modus vivendi.
For texts see Vincenzio Nussi, Quinquaginta conventiones de rebus ecclesiasticis (Rome, 1869; Mainz, 1870); Branden, Concordata inter S. Sedem et inclytam nationem Germaniae, etc. (undated). On the nature and obligation of concordats see Mgr. Giobbio, I Concordati (Monza, 1900); idem, Lezioni di diplomazia ecclesiastica (Rome, 1899-1903); Cardinal Cavagnis, Institutiones juris publici ecclesiastici (Rome, 1906). For the French concordats see A. Baudrillard, Quatre cents ans de concordat (Paris, 1905); Boulay de la Meurthe, Documents sur la négociation du concordat et sur les autres rapports de la France avec le Saint-Siège (Paris, 1891-1905); Cardinal Mathieu, Le Concordat de 1801 (Paris, 1903); E. Sevestre, Le Concordat de 1801, l'histoire, le texte, la destinée (Paris, 1905). On the relations between the church and the state in various countries see Vering, Kirchenrecht, §§ 30-53.
 These are arranged under thirty-five distinct heads in Nussi's Quinquaginta conventiones de rebus ecclesiasticis (Rome, 1869).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)