BUENOS AIRES, ARCIDIOCESI of. — Capital of Argentina, B. A. was founded in 1536 by Pietro de Mendoza and rebuilt in 1580 by Giovanni de Garay after its complete destruction by the Indians. Its religious development was slow, so that it acquired episcopal dignity only in 1620 (and not in 1582, as some writers have believed), by virtue of a bull of Pope Paolo V, which detached its territory from the Paraguayan see of La Asunción, while retaining for it the title of the Most Holy Trinity, which the city itself bore. B. A. was therefore not the first bishopric of modern Argentina, since the diocese of Tucumán already existed from 1570, its bishop residing first at Santiago del Estero and, from 1699, at Cordova. The two sees depended on the metropolitan see of La Plata or Las Charcas, later called Sucre, in present-day Bolivia.
The first bishop of B. A. was the Carmelite Pietro Carranza, who governed the diocese until 1655; he was succeeded by eminent prelates, though not without interruption, since there are several gaps in the succession of bishops of that see, especially during the French Revolution and the separatist crisis of the provinces of La Plata in the first half of the last century. The papal instrument of erection of 6 April 1620 states: “The city of the Most Holy Trinity of Puerto de Buenos Aires in the West Indies is situated in the province of the Río de La Plata and has its cathedral church under the invocation of St Martin; nevertheless, it does not possess the dignity, canonries, prebends, and other benefices necessary for a cathedral, but these shall be established by the present bishop after provision has been made by the Catholic king.” As the importance of the city of B. A. grew through the commercial development of its port, and since it was the capital of the viceroyalty of La Plata from 1776 to 1810, the diocese rose in importance to first place among all those along the Uruguay, Paraná, and Salado rivers. After the provinces of La Plata emancipated themselves from Spain, with which they waged a harsh war from 1810, supported chiefly by the government of B. A., consideration was given to raising that see to a metropolitan see; but this had to wait until 1865, owing to Spain’s opposition to recognition of the new situation of those dioceses, and subsequently because of the civil and military dissensions that prevented the internal consolidation of the nation. For these reasons, the nation’s episcopal sees remained without bishops for many years. From that year (1865) until our own time, B. A. was the only Argentine archbishopric and had as suffragan sees the ancient see of Cordova del Tucumán and the new see of Salta, erected in 1806; these were joined by those of S. Giovanni del Cuyo in 1834 and Paraná in 1854, and, at the end of the century, namely in 1897, by the other three of La Plata, Santiago del Estero, and the new see of Tucumán, detached from Salta. As the Argentine population then grew enormously owing to European immigration, Pius X gave B. A. two further suffragan sees in 1910, Catamarca and Corrientes. Nevertheless, the metropolitan territory of B. A. still remained enormously extensive, embracing, in addition to the district of the federal capital, the island of Martín García and the provinces of Río Negro, Chubut, Santa Cruz, and Tierra del Fuego. Finally, in 1934, with the erection of ten other dioceses and the elevation of six existing ones to metropolitan sees, the metropolitan see of B. A. lost all its former suffragans, receiving only three of the new ones, namely Mercedes, Azul, and S. Nicolás. Its still extensive territory contains a splendid religious life, as was demonstrated by the great International Eucharistic Congress of 1934 and as is evident from its numerous institutions of culture and charity. At present (1948) it has 115 parishes, with 340 diocesan priests and 548 religious priests. The inhabitants number 3,050,000, of whom 3,000,000 are Catholics. — Vedi Tav. XIII.