H.B. Thomas Mar Themotheos Metropolitan, Catholicose designate, is enthroned as the seventh Catholicose of Indian Orthodox Church on October 31, 2005. The consecration of the new Catholicose was celebrated in the midst of Holy Eucharist offered at Parumala Seminary Church with H.G. Thomas Mar Makarios Metropolitan as chief celebrant. After the declaration of the Synod's decision to enthrone H.B. Thomas Mar Themotheos as the new Catholicose by the Secretary of Holy Synod H.G. Thomas Mar Athanasios Metropolitan, the three part ordination was led by the senior most Metropolitan H.G. Geevarghese Mar Osthathios. All other Metropolitans of the Church were the co-celebrants of the ordination. The new Catholicose of Malankara is named as Mar Basalios Marthoma Didimos I and he is the 20th Malankara Metropolitan and 90th Catholicose of the East. Mar Themotheos was elevated to the position in place of Catholicose Marthoma Mathews II had expressed his desire to abdicate his position owing to old age and ill-health.

The newly ordained Catholicose, Mar Basalios Marthoma Didimos I was the Catholicose designate of the Church for last 13 years. 84 year old Metropolitan who is a voracious reader, is a symbol of simplicity and prayer life. Born to Ittiyavara of Nedumpram Mulamoottil family in Thiruvalla and Sosamma of Chiramel family at Mavelikkara as their fourth son on 29 October 1921, C.T. Thomas was inspired by Thomas Ramban [Later Thomas Mar Dionasios Metropolitan] to spiritual vocation while he was servicing in the Altar at Mavelikkara Puthiyakavu Church. Thomas accepted Ramban as his Guru and mentor and joined Tabor Dayara at Pathanapuram embracing ascetic life in 1939. Dayara was in its primitive stage as the monastery was started by Thomas Ramban only in 1929. Ashram was a thatched shed, and the monks were sleeping in nearby school rooms. They had to do hard work during the day, tilling the soil and doing cultivation for their living. Thomas had completed his high school education in the Dayara School and passed Intermediate from C.M.S College Kottayam.

C.T. Thomas was ordained to first stage of deaconate in March 11, 1942 at Karappuzha Mar Gregorios Church. During the feast of Ascension on May 22, 1947 he was ordained as a full deacon by the Catholicose Basalios Geevarghese II. Dn. Thomas had undergone his theological training at Tabor Dayara under the discipleship of Thomas Mar Dionasius and Augen Mar Themotheos. On January 25, 1950 Augen Mar Themotheos ordained Dn. Thomas as a priest at Tabor Dayara. Fr. C.T. Thomas took his B.A. degree from National College Tiruchirappally, B.T. from Maston Training College, Madras. He had served as headmaster of Ponnayya High School, Thiruchirapalli and St. Stephen's High School, Pathanapuram. After completing his M.A. in English Literature from Christ Church College, Kanpur in 1961, Fr Thomas became Professor of English Department in St. Stephen's College, Pathanapuram and later Vice-Principal of the College. On May 16, 1965 Fr. Thomas was ordained as a Ramban.

The Malankara Association held at M.D. Seminary Kottayam elected Thomas Ramban to Lord's episcopate. On August 24, 1966 Basalios Augen Catholicose ordained Thomas Ramban as Bishop with title Thimotheos at Kolencherry Church. Metropolitan took charge of Malabar Diocese as Asst. Metropolitan to Pathros Mar Osthathios. When Mar Themotheos took over the diocese, Malabar was a very poor diocese even without an Aramana for Thirumeni to live in. In the early days he started the diocesan work living in an old one room kitchen annexed to a Cathedral in Calicut district and traveling by public service buses. On February 2, 1969 Mar Themotheos Thirumeni became diocesan Metropolitan after Pathrose Mar Osthathios Thirumeni expired. In 1972, when his Guru Thomas Mar Dionasius expired, Mar Themotheos became Superior of the Tabor Dayara and associated educational excellences.

Mar Themotheos continued to hold post of the President of the Orthodox Youth Movement and General Superior of Mount Tabor Dayara and Convent in Pathanapuram. Malankara Association held at Parumala Seminary on 1992 September 10, elected him as Catholicose designate.