Kothamangalam Subbu was born in the year 1910 in the village Kannaariyendal near Karaikudi, to Mahalinga Iyer and Gangammal. His actual name was SM Subramaniam. He studied upto the eighth form in Karaikudi, after which commercial compulsions forced him to take up clerical jobs, before he made the plunge in theatre and writing.

Subbu’s interests varied from photography to examining gemstones. A person with a friendly disposition, Subbu was close to several persons of eminence including TV Sundaram Iyengar (founder of TVS Group), PS Kumaraswamy Raja (former chief minister of TN), R Venkatraman and Sarvapalli Radhakrishnan (former Presidents of India).