Of Irish descent, Thomas Cullinan was born in Elands Post near Seymore, Cape Colony on 12 February 1862.

However Cullinan succeeded in purchasing the land for £52,000 from Prinsloo's daughter, who inherited the farm after her father's death.

[4] He was a member of the Transvaal Legislative Assembly and the first Union Parliament of 1910,[4] representing the Pretoria Western district.

[2] The investiture was carried out by the Duke of Connaught, representing King George V.[5] Sir Thomas Cullinan died in 1936, aged 74.

He had a family of ten children,[2] and was the grandfather of Patrick Cullinan, a prominent South African poet.