As an earnest student of canon law Paul V. was too inclined to maintain all the rights and privileges of the Church as they were expounded in the decretals of the Middle Ages. This attitude of mind brought him into a prolonged and inglorious conflict with the republic of Venice. This latter state, regardless of the /privilegium fori/imprisoned two clerics without reference to the ecclesiastical authorities, and about the same time gave great offence by passing laws rendering it difficult for the Church to acquire ownership of landed property, to build new churches or monasteries, or to found new religious orders or societies. Paul V. lodged a solemn protest against these innovations. When his demands were not complied with he issued a sentence of excommunication against the Doge, Senate, and Government, and later on he placed Venice under interdict (1606). The quarrel was so bitter that at one time it was feared that it might end in separating the republic from the centre of unity. Cardinals Baronius and Bellarmine entered the lists in defence of the Pope, while the notorious ex-Servite, Paul Sarpi[10] (1552-1623), undertook to reply to them on behalf of Venice. The government forbade the promulgation of the interdict, and threatened the most severe punishment against all clergy who should observe it. With the exception of the Jesuits, Capuchins, and Theatines who were expelled, the clergy both secular and regular took no notice of the interdict. It was feared that in the end the issues could be decided only by war in which Spain was prepared to support the Pope, but through the friendly intervention of Henry IV. of France peace was concluded without any very decisive victory on either side (1607). The clergy who were expelled for obeying the interdict were allowed to return except the Jesuits. These latter were permitted to settle in Venice again only in 1657.
On the death of Paul V. Cardinal Ludovisi ascended the papal throne under the title of Gregory XV. (1621-23). The new Pope had been educated by the Jesuits, and had risen rapidly in the service of the Church. At the time of his election he was old and infirm, but by the appointment of his nephew Ludovico to the college of cardinals he secured for himself an able and loyal assistant. To put an end to several abuses that had taken place in connexion with papal elections he published the Bull, /Decet Romanum Pontificem/ (1622), in which were laid down minute regulations about conclaves, the most important of which were that the cardinals should vote secretly, that they should vote only for one candidate, and that no elector should vote for himself.[11] In providing funds for the assistance of the Catholic missions Gregory XV. was very generous as was also his cardinal-nephew. The success of the missionaries had been so great, and the conditions of the various countries in which they laboured so different, that proper supervision of the new provinces of the Church was by no means easy. Gregory XIII. and Clement VIII. had appointed commissions to look after the spiritual wants of particular districts, but it was reserved for Gregory XV. to establish a permanent congregation, /De Propaganda Fide/ (Bull, /Inscrutabili/, 1622) to superintend the entire field of Catholic missions. He had the honour, too, of canonising St. Ignatius of Loyola, St. Francis Xavier, and St.
Philip Neri, and of approving the foundation of several new religious orders.
During the Thirty Years' War he afforded every possible assistance to Ferdinand II., and helped to secure the Palatinate for Maximilian of Bavaria on the expulsion of Frederick. In return for this favour Maximilian presented the Pope with a goodly portion of the library of Heidelberg. By the judicious interposition of Gregory XV. war was averted between Spain and Austria on the one side and France, Venice, and Savoy on the other regarding the possession of the Valtelline, while in England, though the Spanish Match which he favoured was broken off, he succeeded in securing some respite for the persecuted Catholics.
In the conclave that followed upon the death of Gregory XV. Cardinal Barberini received the support of the electors and was proclaimed Pope as Urban VIII. (1623-44). The new Pope was a man of exemplary life whose greatest fault was his excessive partiality towards his relatives, though it must be said that some of the relatives on whom he bestowed favours were by no means unworthy of them. As a native of Florence he seems to have caught up something of the spirit of classical learning for which that city had been so renowned, as was shown unfortunately too clearly in the Breviary that he published in 1632. He issued the Bull, /In Coena Domini/ in its final form, founded a national college in Rome for students from Ireland, and issued a series of strict and minute regulations on canonisation and beatification, many of which remain in force till the present time.
The interests of the foreign missions were specially dear to the heart of Urban VIII. To provide a supply of priests for them he established the celebrated /Collegium Urbanum/ (1627), and established there a printing-press for the use of the missionaries. He reduced the number of holidays of obligation, opened China and Japan, till then reserved for the Jesuits, to all missionaries, and forbade slavery of whatsoever kind in Paraguay, Brazil and the West Indies.
For many reasons the political policy of Urban VIII. has been criticised very severely. Too much money was wasted by him in fortifying the Papal States and on the disastrous war with the Duke of Parma (1641-44). He has been blamed also for his failure to support Ferdinand II. more energetically during the Thirty Years' War, but in reality this hostile view is based largely on a distorted view of the war itself and of the policy of the Pope. It is not true that the Pope sympathised with Gustavus Adolphus or that he grieved over his death.