Padroado in the context of Américo Ferreira dos Santos Silva

The Saint Thomas Christians, also called Syrian Christians of India, Marthoma Suriyani Nasrani, Malankara Nasrani, or Nasrani Mappila, are an ethno-religious community of Indian Christians in the state of Kerala (Malabar region), who, for the most part, employ the Eastern and Western liturgical rites of Syriac Christianity. They trace their origins to the evangelistic activity of Thomas the Apostle in the 1st century. The Saint Thomas Christians had been historically a part of the hierarchy of the Church of the East but are now divided into several different Eastern Catholic, Oriental Orthodox, Protestant, and independent bodies, each with their own liturgies and traditions. They are based in Kerala and they speak Malayalam. Nasrani or Nazarene is a Syriac term for Christians, who were among the first converts to Christianity in the Near East.

Historically, this community was organised as the Province of India of the Church of the East, by Patriarch Timothy I (780–823 AD) in the eighth century, it was served by bishops and a local dynastic archdeacon. In the 14th century, the Church of the East declined in the Near East, due to persecution from Tamerlane. Portuguese colonial overtures to bring St Thomas Christians into the Latin Church of the Catholic Church, administered by their Padroado system in the 16th century, led to the first of several rifts (schisms) in the community. The attempts of the Portuguese culminated in the Synod of Diamper, formally subjugating them to the Portuguese Padroado and imposing upon them the Roman Rite of worship. The Portuguese oppression provoked a violent resistance among the Thomasine Christians, that took expression in the Coonan Cross Oath protest in 1653. This led to the permanent schism among the Thomas' Christians of India, leading to the formation of Puthankoor or Puthankūttukār ("New allegiance" ) and Paḻayakūṟ or Pazhayakūr ("Old allegiance") factions. The Paḻayakūṟ comprise the present day Syro-Malabar Church and Chaldean Syrian Church which continue to employ the original East Syriac Rite. The Puthankoottukar, who continued to resist the Catholic missionaries, organized themselves as the independent Malankara Church and entered into a new communion with the Syriac Orthodox Church of Antioch, inheriting from them the West Syriac Rite, replacing the old East Syriac Rite liturgy.

Ecclesiastical Nagasaki refers to the period during which the city of Nagasaki was administered by the Jesuits under the nominal authority of the Ōmura clan.

Contrary to some accounts, it was not a Portuguese colony. Portuguese representatives had only commercial and religious privileges under the Padroado.

The Synod of Diamper (Udayamperoor Synod) (Malayalam: ഉദയംപേരൂർ സൂനഹദോസ്, romanized: Udayampērūṟ Sūnahadōs), held at Udayamperoor (known as Diamper in non-vernacular sources) in June 1599, was a diocesan synod, or council, that created rules and regulations for the ancient Saint Thomas Christians (also known as Mar Thoma Nasranis) of the Malabar Coast, a part of modern-day Kerala state, India, formally subjugating them and downgrading their whole Metropolitanate of India as the Diocese of Angamale, a suffragan see to the Archdiocese of Goa administered by Latin Church Padroado missionaries. This synod also introduced forced Liturgical Latinisation and the eschewal of local practices and beliefs, leading to a significant ecclesial protest by Saint Thomas Christians known as Coonan Cross Oath and a subsequent schism in the mid-17th century.

The Paḻayakūṟ (Pazhayakoor; English: "Old Allegiance"), also known as Romo-Syrians or Syrian Catholics of Malabar, are the Saint Thomas Christians who use the East Syriac Rite and claim apostolic origin from the Indian mission of Thomas the Apostle in the 1st century AD.

The Saint Thomas Christians were originally in full communion with the Church of the East in Persia, from whom they inherited the East Syriac liturgical rite. Through the Schism of 1552, a faction of the Church of the East entered the Catholic Church. Following the 1599 Synod of Diamper, they were placed under the Latin Church's Padroado missionaries, who took over the jurisdiction of Angamaly. After the Coonan Cross Oath of 1653, which constituted a secession from the Padroado, the Paḻayakūṟ quickly returned to the Catholic Church as East Syriac Catholics under Archbishop Palliveettil Chandy.

The Malankara Church, also known as Malankara Syrian Church, was the unified body of Puthankur Saint Thomas Christians who claim origins from the missions of Thomas the Apostle. This community, under the leadership of Thoma I, opposed the Padroado Jesuits as well as the Propaganda Carmelites following the Coonan Cross Oath of 1653, which was taken to resist Western Catholic influences.

The Malankara Church eventually came under the influence of the Syriac Orthodox Church but later split successively, leading to the creation of churches across various denominations and traditions. The Malankara divisions and branchings have resulted in the present-day Jacobite Syrian Christian Church, Malankara Orthodox Syrian Church, Malankara Mar Thoma Syrian Church, Malabar Independent Syrian Church, Syro-Malankara Catholic Church, the Saint Thomas Anglicans of the Church of South India and the St. Thomas Evangelical Church of India.

The patronato (lit. 'patronage') system in Spain (and a similar padroado system in Portugal) was the expression of royal patronage controlling major appointments of Church officials and the management of Church revenues, under terms of concordats with the Holy See. The resulting structure of royal power and ecclesiastical privileges, was formative in the Spanish Empire. It resulted in a characteristic constant intermingling of trade, politics, and religion. The papacy granted the power of patronage to the monarchs of Spain and Portugal to appoint clerics because the monarchs "were willing to subsidize missionary activities in newly conquered and discovered territories."

The Titular Patriarch of the East Indies (Latin: Patriarcha Indiarum Orientalium; Patriarchatus Indiarum Orientalium for Titular Patriarchate of the East Indies) in the Catholic hierarchy is the title of the Archbishop of Goa and Daman in India; another of his titles is the Primate of the East. Unlike the patriarchs and the major archbishops of the Eastern Catholic Churches sui juris, the Patriarch of the East Indies is within the Latin Church similar to the residential Latin Patriarchs of Venice, Lisbon and Jerusalem, enjoying only an honorary position. Like the Patriarch of the West Indies, the Patriarch of the East Indies is a titular patriarchate unlike the residential Latin Catholic Patriarchs. The title is attached to the Archbishop of Goa and Daman, the diocesan ordinary of the Archdiocese of Goa and Daman and the metropolitan archbishop of the Province of Goa and Daman.

This title of Patriarch or Primate of the East Indies was conferred upon the Archbishop of Goa as a result of a concordat between the Holy See and the Crown of Portugal; concerning the link between religious and political aspects of Portuguese India, known as the Padroado system. Later, with Portugal's decline as a colonial power, a difficult period resulted that was resolved by a further agreement by which Portugal renounced its rights of patronage. In this way the episcopal appointments in actual or former Portuguese colonial territory reverted to the common provisions of Latin ecclesiological law, with no intermediary between them and the Holy See. As regards India, this meant that the Holy See was free to make appointments to the episcopate in regions such as British Bombay.