Leopold Alexander Pars lived with his two parents Laura Unwin and Albertus McLean Pars. His father Albertus worked as an accountant for a firm who manufactured farm machinery but what he really loved was music. He was also a regular playing the organ at his church. Leopold was known to all his friends as Alan from his university day onward. He had a sister Dora who was four years older than him. There was also another member of the house, Aleathea Starling she was the nursemaid for the two children but she also looked after the family home.
Leo's School was in London after his family movd to Shepherd's Bush in 1899 when he was three years old. They stayed there until 1926 when they moved to a new house in Acton, they stayed there for the rest of their lives. Leopold was educated at Latymer Upper School in Hammersmith where in addition to his academic work, he took place in sport, in athletics. In December 1914 ge won a foundation Scholarship in Mathematics and Physics to study at Jesus Collee , Cambridge. He went to that college to begin his studies In October 1915 but after missing two terms to his health, he waited until 1917 before he sat Part 1 of the Mathematical Tripos. Despite his illnesses Pars took place in Athletic events at University where he won the mile in the Inter-University sports. Pars became known when he was an undergraduate, then took a London University M.Sc. and in 1921 he was the first smith's prizeman at Cambridge
After retirement from teaching he remained president of Jesus College until 1964. On leaving this role he visited the Florida Atlantic University, the University of Sydney, and his travels took him to visit friends in Trinidad, New Zealand, Tasmania, and Uganda. Although retirement he lives at his home in Acton with his sister Dora he continued to make visits to exotic places but he retained his connected with Jesus College. He remained on the College council until the end of his life.