His Holiness Baselios Marthoma Didymus I was catholicos of the East and Malankara Metropolitan is the 90th prelate seated on The Apostolic Throne of St. Thomas. He is the 7th Catholicos in Malankara after the establishment of the Catholicate here in 1912 and the 20th Malankara Metropolitan.

Born on October 29, 1921, in Mavelikara in Pathanamthitta District of Kerala as the son of the late Mulamootil Ittyavirah Thomas and the late Chiramel Sosamma, the boy C. T. Thomas had his early education in a local school. At the age of 17, he became a member of the Mount Tabor Dayara (Monastery), Pathanapuram, where he completed his high school education and was initiated to a strict monastic life. As a disciple of His Grace Thoma Mar Dionysius, C. T. Thomas began his monastic training and theological studies at Tabor Dayara, and later, continued his training under the able guidance of H. H. the Catholicos Baselios Geevarghese II and H. H. Baselios Augen I. He was ordained as Koruyo on March 11, 1942, and as Deacon on May 22, 1947. On January 25, 1950, H. H. the Catholicos Baselios Geevarghese II ordained D. C. T. Thomas as priest. Fr. C. T. Thomas continued his studies and earned B.A., M.A. and L.T. degrees. A farsighted educationalist, Fr. C. T. Thomas served as Vice Principal of St. Stephen’s College, Pathanapuram.

A strict ascetic, he was professed as Ramban (Monk) on May 16, 1965, by H. H. Baselios Augen I. The Malankara Syrian Christian Association held at M. D. Seminary, Kottayam, on December 28, 1965, chose him to be elevated to the rank of Episcopa. On August 24, 1966, H. H. Baselios Augen I consecrated C. T. Thomas Ramban as bishop with the name Thomas Mar Themothios. He took charge of the Malabar Diocese where he served the Church for 39 years, at first as the Assistant bishop and then as Metropolitan. On September 10, 1992, Mar Themothios was elected as Assistant and Successor to the Catholicos of the East and Malankara Metropolitan by the Malankara Syrian Christian Association.

On October 29, 2005, Mar Themothios took over as the Malankara Metropolitan from his illustrious predecessor Moran Mar Baselios Marthoma Mathews II. On Monday, October 31, 2005, at the hallowed precincts of Parumala Seminary, he was consecrated as the 7th Catholicos of the throne of St. Thomas in India and the Supreme Head of the Malankara Orthodox Church, with the name Baselios Marthoma Didymus I. His Holiness continues to serve God and humanity with the grace and humility and self abnegation of a true ascetic.