Born 25th October 1893 in Little Hadham, Herts. Son of Thomas and Amelia Ann Brett. His father was a farm servant. He was Baptised on the 7th January 1894 in the Parish of Much Hadham, Herts. In 1901 they were living at "Armoury" near Sawtrees farm in Thundridge. In 1911 they were at Fabdens, Youngsbury, where Jonas is working as a farm labourer, and his father is a widower. The 1911 Census shows him living at Fabdens, Youngsbury, Ware, Herts, with his widower father, was now a widower and his occupation is given as Working on Farm.
Enlisted at Hertford.