Oliver was born on October 15th, 1917. Oliver's father was Thomas Thomas and his mother was Myfanwy Thomas. His paternal grandparents were David Thomas and Ann Williams; his maternal grandparents were James Thomas and Harriet Davies. He had five brothers and two sisters, named David , Gomer, Emrys, John, Mansel, Harriet and Doris. He was the fourth oldest of the eight children. He died due to natural causes or old age at the age of 80 on January 27th, 1998.