Naturalis Historia (Natural History) by Pliny the elder (1st Century), Periplus of the Erythraean Sea by an unknown author (1st or 3rd century), Muziris papyrus, an agreement by two merchants in Egypt and Muziris (2nd century), presence of Roman, Greek and Persian antiquities etc. from BC onwards until early centuries are few examples.

Suriyani or Syriac, a dialect of Aramaic, is the language that was widely used in the Middle East until 8th century, before Arabic replaced it. East Syriac and West Syriac are the two dialects of Syriac. East Syriac was the living language in Persian Sassanids (3rd-7th centuries) and west Syriac was developed in the emperors of Greek Byzantium, who waged war against each other. There are differences in the scripts, vowel system and pronunciation for these two dialects, but both these dialects have similar vocabulary grammatical structure.

It is now in modern Iraq, previously it was the capital of the Sassanid Empire of Persia. In 410 AD at the Council of Mar Isaac, the Bishop of Seleucia-Ctesiphon, bishop of Seleucia-Ctesiphon declared himself as "Catholicos of all the Orient" and equated his see with the sees of Jerusalem, Antioch, Alexandria and Rome. The council declared that the Church would adhere to the decisions of the Council of Nicea and Nicene Creed. Prior to the Synod, see of Antioch had theoretical jurisdiction over Persia although this jurisdiction was vague.

This Church was originated beyond the borders of Roman Empire and spreaded through central Asia, India, Arabia, China, Tibet and until far Eastern countries like Malaysia and Indonesia.

The Church is also known as Nestorian Church. Nestorius, the Patriarch of Constantinople has happened to be condemned as a heretic at the First Ecumenical Council of Ephesus. After the schism, many of his supporters split with the rest of the Christendom and over the next decades a number of them relocated to Persia. Thereafter Nestorian doctrine became the official position of the Church of the East.

The separation of Persian Church was evident even earlier. In 410 AD at the Council of Mar Isaac, the Bishop of Seleucia-Ctesiphon-the head of the CoE, declared himself as "Catholicos of all the Orient" and equated his see with the sees of Jerusalem, Antioch, Alexandria and Rome. The council declared that the Church would adhere to the decisions of the Council of Nicea and Nicene Creed. Prior to the Synod, see of Antioch had theoretical jurisdiction over Persia although this jurisdiction was vague.

East Syriac rite is the liturgical rite practiced by the Assyrian Church of the East (Chaldean Syrian Church in India), Chaldean Catholic Church and Syro-Malabar Church. This rite and the East Syriac language were completely developed within Persian Empire. This is the ancient rite of Mar Thoma Nasranis prior to the arrival of Portuguese and its modified form is still practiced by the Churches derived from Pazhayakoor faction. Puthenkoor faction also used this rite until the West Syrian rite was completely adopted by mid nineteenth century.

West Syriac is part of the Antiochene liturgical rite, originated in the ancient Patriarchate of Antioch, is practiced by the Syriac Orthodox Church and churches related to or derived from it. This rite and the West Syriac language were completely developed outside Persian Empire or the regions within Roman Empire, particularly Antioch and near by provinces. This rite was formed by adapting the old Greek liturgy of Antioch into Syriac. This liturgy is used by Churches derived from Puthenkoor faction. Adaptation of Antiochean liturgy among the Puthenkoor Nasranis was not immediately after the schism during 1653-65 AD, but has taken more than a century to complete, from the 1750s to the 1860s.

East Syriac rite is the liturgical rite practiced by the Assyrian Church of the East (Chaldean Syrian Church in India), Chaldean Catholic Church and Syro-Malabar Church. This rite and the East Syriac language were completely developed within Persian Empire. This is the ancient rite of Mar Thoma Nasranis prior to the arrival of Portuguese and its modified form is still practiced by the Churches derived from Pazhayakoor faction. Puthenkoor faction also used this rite until the West Syrian rite was completely adopted by mid nineteenth century.

West Syriac is part of the Antiochene liturgical rite, originated in the ancient Patriarchate of Antioch, is practiced by the Syriac Orthodox Church and churches related to or derived from it. This rite and the West Syriac language were completely developed outside Persian Empire or the regions within Roman Empire, particularly Antioch and near by provinces. This rite was formed by adapting the old Greek liturgy of Antioch into Syriac. This liturgy is used by Churches derived from Puthenkoor faction. Adaptation of Antiochean liturgy among the Puthenkoor Nasranis was not immediately after the schism during 1653-65 AD, but has taken more than a century to complete, from the 1750s to the 1860s.

Reformed Churches have partly or fully accepted protestant reformations of Western Christianity initiated by Martin Luther, John Calvin and other early Protestants. Mar Thoma Syrian Church and Malabar Independent Church have undergone such reformation as a result of their interactions with the Anglican Church. Mar Thoma Church is in full communion with the Anglican Church.

Oriental Orthodox Churches are the Churches of East that recognise only the first three ecumenical councils — the First Council of Nicaea, the First Council of Constantinople and the First Council of Ephesus. It should noted that the ancient Church of the East do not fall into this category. Also they do not belong to the Eastern Orthodoxy.

1553 AD: Schism within the Church of the East

Due to difference in opinion about the hereditary succession of Patriarchal position, Monk Yohannan Sulaqa in 1552 AD, went to Rome to be consecrated and installed Patriarch. Pope Julius III installed him as Patriarch in 1553 AD. His successors till the end of the sixteenth century were 'Abdiso' (1555-1571), 'Aithalla' (1578-1580), and 'Denha Simon' (1581-1600). Abdiso visited Rome and obtained confirmation and the Pallium. Aithalla owing to the old age could visit Rome, nor did he get confirmation from Rome before his death. Denha Simon got confirmation and the Pallium from Rome. It was this Patriarch who was in open communion with Rome that was condemned by Dom Menezes as heretic in the Udayamperoor Sunahados. Since the arrival of Mar Yousef Sulaqa, the brother of Yohannan Sulaqa, in Malabar in 1555 AD as a prelate, the Malabar Church became in full communion with the Church of Rome.

1599 AD: The so-called Udayamperoor Sunhados

On June 20, 1599, for commandeering obedience to the supreme Bishop of Rome, the Portuguese Archbishop Menezes of Goa summoned a synod at Udayamperoor. They sought the help from the Rajah of Kochi (Cochin). The Rajah of Kochi and local Hindu Chieftains threatened those who refused to attend the Sunhados, as commanded by the Portuguese. The Rajah had even declared that all assets of Mar Thoma Nazrani Churches that stay away from the Sunhados would be forfeited. The delegates (153 priests and 660 faithful), headed by Archdeacon Giwargis d’Sleeva (George of the cross), who attended the Sunhados were forced to accept the decrees read out by the Archbishop Menezes as the military of Portuguese and Kochi Rajah surrounded the Church. Thus Mar Thoma Nasranis were subjugated under the Roman Catholic hierarchy of Goa. A Church that had origins from Saint Thomas the Apostle with unrestricted jurisdiction became a mere suffragan under the Latin archdiocese of Goa.

Arrival of European Traders

After years of break, a European traveller of Portuguese origin, Vasco De Gama reaches in the Malabar Coast at Kappadu, near Kozhikode, a region under the dominance of Zamoothiri (Zamorin). In. He visited Kochi again in 1502 and 1524. Portuguese astonished after seeing the Christians of Malabar, but later they reaslised that they were under the spiritual guidance of Chaldean Patriarch of Babylon. In the view of Roman Pontiff, the Chaldean Church was heritic as they were the followers of Nestorius who was the Patriarch of Constantinople from 428 AD until 431 AD.

1653 AD: Revolt of Nasranis

The frustration of the Nasranis reached its zenith in 1653 with the 'Coonan cross oath'. The Coonan Cross Oath was the revolt by Nasranis against the Portuguese as a result of the dominance that they have exerted on the Church of Nasranis since the so-called Synod of Udaymperoor in 1599. It took place on 3 January 1653 at Mattancherry in Cochin. At the time of Coonan cross oath, only 400 out of 3,00,000 Saint Thomas Christians stood with the Portuguese missionaries (Jesuits). Result of the Coonan Cross oath was that an Independent Church under the leadership of the Arkkadiyokan was formed.

Aftermath events divided the community into two factions: Pazhayakoor, under the leadership of Palliveettil Chandy Methraan, with a legitimate Bishopric consecration and the Puthenkoor under the leadership of Arkkadiyaokkan or Mar Thoma I, without a legitimate Bishopric consecration.

Church of the East (CoE)

This Church was originated beyond the borders of Roman Empire and spreaded through central Asia, India, Arabia, China, Tibet and until far Eastern countries like Malaysia and Indonesia.

The Church is also known as Nestorian Church. Nestorius, the Patriarch of Constantinople has happened to be condemned as a heretic at the First Ecumenical Council of Ephesus. After the schism, many of his supporters split with the rest of the Christendom and over the next decades a number of them relocated to Persia. Thereafter Nestorian doctrine became the official position of the Church of the East.

The separation of Persian Church was evident even earlier. In 410 AD at the Council of Mar Isaac, the Bishop of Seleucia-Ctesiphon-the head of the CoE, declared himself as "Catholicos of all the Orient" and equated his see with the sees of Jerusalem, Antioch, Alexandria and Rome. The council declared that the Church would adhere to the decisions of the Council of Nicea and Nicene Creed. Prior to the Synod, see of Antioch had theoretical jurisdiction over Persia although this jurisdiction was vague.

Roman Catholic Church

Roman Catholic Church is the Church that originated in Roman empire. The head of the Church Patriarch of Rome, popularily known as "Pope". The Church follows the Latin liturgical rite and maintains that Pope is the successor of Saint Peter the Apostle.

Palliveettil Chandy Methran dies

It was only due to the political situation that the Pazhayakoor faction got a native bishop Palliveettil Chandy Methraan. Otherwise Sebastini would have continued in his position. It is interesting to note that Rome tactfully did not continue the indigenous bishopric of Malabar after the death of Palliveettil Chandy Methran in 1687 AD. If they were sincere, we would have seen more indigenous bishops immediately after the death of Palliveettil Chandy Methraan.

1773 AD: First split within the Puthenkoor faction

Malabar Independent Church is established.

1843-1885 AD: Second split within the Puthenkoor faction

Mar Thoma Syrian Church is established.

1862-1904 AD: Schismatic period of the Pazhayacoor faction

Formation of Chaldean Syrian Church

1887 AD: Formation of the vicariates for Syro-Malabar Church

Two independent Vicariates for the Syro-Malabar Church are formed: 1) Kottayam(present Changanaseri) and 2) Thrissur. The original see of the Church (Angamaly) was suppressed to wipe out any trace of an independent Church with unrestricted jurisdiction. Rome renamed the Church (Church of Saint Thomas Christians) to Syro-Malabar Church, which by any means reflects her origin.

The Church had to wait until 1896 AD to get their first indigenous bishop. If the line of Palliveettil Chandy Methran was continued immediately afterwards, or Mar Kariyattil had an immediate successor after his death, the alliance of Pazhayakoor faction with Rome would have been meaningful and the reunion with Puthenkoor faction would have become a reality. They had to wait more than 200 years to get nominal freedom to keep their tarditions and liturgical rite.

1912-1974 AD: Third period of unsteadyness within the Puthenkoor faction

Formation of Malankara Syriac Orthodox Church and Jacobite Syrian Christian Church.

1932 AD: Fourth split within Puthenkoor faction

Formation of Syro-Malankara Catholic Church.

Pazhayakoor (Old Alliance)

The events after the Coonan Cross Oath, the historical revolt of Nasranis against the authority of Europeans, divided the community into two factions: Pazhayakoor, under the leadership of Palliveettil Chandy Methraan, with a legitimate Bishopric consecration and the Puthenkoor under the leadership of Arkkadiyaokkan or Mar Thoma I, without a legitimate Bishopric consecration.

Pazhayakoor faction continued their alliance with Rome and in the later centuries their liturgy and lifestyle have became Latinised. Syro-Malabar Church, the majority among the Pazhayakoor faction still struggle to get freedom from the Latinisation.

Puthenkoor (New Alliance)

The events after the Coonan Cross Oath, the historical revolt of Nasranis against the authority of Europeans, divided the community into two factions: Pazhayakoor, under the leadership of Palliveettil Chandy Methraan, with a legitimate Bishopric consecration and the Puthenkoor under the leadership of Arkkadiyaokkan or Mar Thoma I, without a legitimate Bishopric consecration.

Puthenkoor faction rejected the authority of Rome and accepted the authority of Syriac Orthodox Church. Gradually, the traditional East Syriac liturgy was replaced with West Syriac. In the later times they got divided into several denominations.