Thumpamon is one of the seven dioceses created after the Mulanthuruthy Synod conducted under the leadership of Ignatius Peter III, Patriarch of Antioch in 1876.

Others are Kottayam, Kandanadu, Angamali, Niranam, Kollam, Kochi.

Konatu Geevarghese Mar Yulios was the first metropolitan and led the diocese from 1876 to 1884.

Thumpamon English Middle School was founded at this time.

The Bishop's house (Aramana) of the diocese was built by Puthencav kochu Thirumeni (Geevarghese Mar Philoxenos) who was also the founder of the then Catholicate High School, at present known as Catholicate College which became the blessing and guiding path of education for the people of Pathanamthitta.