Gradually, order was introduced in all kinds of research work, in which task notable services were rendered by the historical institutes which were established in close relation to the Vatican Archives.
Both methods may be combined, objectively and subjectively; an individual investigator may work at a general theme, while an association may take up the study of a restricted or specific problem, and vice versa.
An exhaustive examination of Italian archives and libraries leads occasionally to a larger view of the subject than was originally intended by the investigator, for whom in this way new questions of importance spring up, the definite solution of which becomes highly desirable.
Experience, therefore, and the detailed study of the numerous repertories, indexes, and inventories of manuscripts, have made it necessary to organize permanently the scientific historical researches carried on in the interest of any given country.
The state institutes investigate all that pertains to national relations or intercourse (religion, politics, economics, science, or art) with the Curia, with Rome, or, for that matter, with Italy.
In addition to the medieval material, numerous extracts and transcripts of a political nature were made from sixteenth- and seventeenth-century documents, transmitted to the Record Office and partly used in the Calendars of State Papers.
The Ecole Française de Rome, originally one with that of Athens, employs almost constantly historical investigators at the Grande Archivio of Naples; they devote themselves to the documents of the Angevin dynasty.
It was founded in 1873, and during the reign of Pius IX, long before the opening of the secret archives, inaugurated its great achievement, the editing of the papal Regesta of the thirteenth century.
A third series is made up of documents selected from the fourteenth-century papal "Regesta", and is entitled "Lettres des papes d'Avignon se rapportant à la France".
The slow progress of so many learned enterprises is a matter of general regret, nor can one always approve the methods employed, though no one can deny the very great utility of these scholarly studies and researches for the history of the papacy and its international relations.
The chaplains of the French National Institute of St-Louis des Français have recently undertaken a work closely related to that of the Ecole Française, the publication in concise regesta-like form of all letters of the Avignon popes.
The director of the institute, Anton de Waal, founded the "Römische Quartalschrift für Archäologie und Kirchengeschichte" as a centre for historical research more modest and limited in scope.
The twelve volumes in which this institute proposes to edit exhaustively the Acts and records of the Council of Trent, represented one of the most difficult tasks which could be set before a body of workers in the Vatican archives.
The library of the institute, besides extensive monographs on various subjects, has published the useful "Repertorium Germanicum", and, in co-operation with the Instituto Storico Italiano, the "Registrum chartarum Italiæ", a series of independent volumes.
The project included a centre for individual Belgian investigators as well as for students assisted by the State, where all might find an adequate library and facilities for securing historical data of every kind.
177–196; P. de Roo, who laboured for several years on the "Regesta" of Alexander VI; Heywood, who compiled the "Documenta selecta e tabulario Sanctæ Sedis, insulas et terras anno 1492 repertas a Christophoro Columbo respicientia", which he published in phototype in 1892.
Special mention should be made here of the studies of Luka Jelic and Conrad Eubel concerning early missionary enterprises, and of an essay by Shipley on "The Colonization of America" (Lucerne, 1899).
Switzerland entered into this peaceful competition by the labours of Kirsch and Baumgarten in 1899, and since the close of the last century many Swiss have visited Rome for Vatican researches, both as individuals and on official missions.
The writer has observed at work in the archives during the last twenty-one years Dominicans, Jesuits, Franciscans, Minor Conventuals, Capuchins, Trinitarians, Cistercians, Benedictines, Basilians, Christian Brothers, Lateran Canons Regular, Vallombrosans, Camaldolese, Olivetans, Silvestrines, Carthusians, Augustinians, Mercedarians, Barnabites, and others.
Since 1879 the archives have welcomed Catholics, Protestants, Hebrews, believers and infidels, Christians and heathens, priests and laymen, men and women, rich and poor, persons of high social standing and plain citizens, of every nation and language.
From the standpoint of subjects treated, Vatican research falls into three parts: If we consider the medieval period under the first of these subdivisions the results obtained are substantially as follows: For certain dioceses, ecclesiastical provinces, regions, or entire countries, all these data, together with other items of information, have in the course of time been gathered, and published, by individuals and by associations.
"Chartularia", or collections of papal Bulls have been published not only for Westphalia, Eastern and Western Prussia, Utrecht, Bohemia, Salzburg, Aquileia, but also for Denmark, Poland, Switzerland, Great Britain, Ireland, and Germany (Repertorium Germanicum), not to speak of other countries.
Many a student of the Vatican archives has devoted all his time to a single subject, e. g. Armellini, "Le Chiese di Roma"; Storm, "Die Obligationen der norwegischen Prälaten von 1311-1523"; Samaran-Mollat, "La fiscalité pontificale en France au l4me siècle"; Berlière, "Les 'Libri Obligationum et Solutionum' des archives vaticanes", for the Dioceses of Cambrai, Liège, Thérouanne, and Tournai; Rieder, "Römische Quellen zur Konstanzer Bisthumsgeschichte (1305-1378)".
The all-pervading activity of the medieval popes has been richly illustrated by various investigators, e. g. Göller on the records of the "Pœnitentiaria"; Kirsch and Baumgarten on the finances (officials, administration) of the College of Cardinals; Baumgarten on the respective offices of the vice-chancellor and the "Bullatores", the residence-quarters of the Curia, its Cursores or messengers; Watzl, Göller, and Schäfer on the finance bureau of the Curia; von Ottenthal on the secretaries and the "Chancery rules"; Tangl and Erler respectively on the "Chancery regulations" and the "Liber Cancellariæ"; Kehr, Berlière, and Rieder on the petition files (libelli supplices), etc.
In a general way the Vatican archives and these new historical Roman institutes have been particularly helpful towards a better knowledge of the ecclesiastico-religious relations of individual dioceses, countries, and peoples with the head of the Church and its central administration.
Melampo and Ranuzzi, following in the footsteps of Meister, have recently published a very useful, but not at all exhaustive, list of all the books and essays of this kind which had appeared up to 1900: "Saggio bibliografico dei lavori eseguiti nell' Archivio Vaticano" (Rome, 1909).