Diwan was second only to prime minister. He kept the records of income and expenditure of the government. In modern terms, he was finance minister.
P. G. N. Unnithan was the last Diwan (Prime Minister) of independent Travancore (Thiruvithamkoor). He succeeded Sir C.P. Ramaswami Iyer on 20 August 1947 following the latter's resignation (subsequent to the attempt on Sir CP's life at the Swathi Thirunal Music academy on 25 July 1947). He chaired the Travancore Constitutional Reforms Committee. He relinquished office on 24 March 1948 when a people's government led by Sri Pattom Thanu Pillai as Prime Minister took over.[1]
Sri PGN Unnithan hailed from the Edassery Pattaveettil Family of Mavelikkara which had a history of high military service to the Travancore Royal Family. His father Ittamar Koil Thampuran was from the Haripad Palace and nephew of Kerala Varma Valiya Koil Thampuran. He married Bhargavi Amma, the daughter of Sri PG Govinda Pillai (Government advocate at Alappuzha) of Pullampilla Pichanattu (Viruthiyathu) Family of Chengannur, who was among the earliest women of the region to support the national movement starting with the boycott of foreign clothes at Alleppey organised and led by the veteran freedom fighter and PGN Unnithan's classmate K. Kumar of Travancore. His sister was married to the son of famed Artist Raja Ravi Varma of the Royal Family of Mavelikkara. He had four children. He died on 5 April 1965.