Leach was born into a Muggle family in Great Britain, sometime in or prior to 1945. He was somehow trained in the magical arts and eventually managed to become the Minister for Magic for Britain and Ireland, being elected at least once.
As Minister for Magic
In 1962, Leach was the first Muggle-born to be appointed to the post of Minister for Magic. Several of the oldest members of the Wizengamot resigned government posts in protest of his appointment. Though Leach was believed to have played a part in England's 1966 World Cup Win, he denied these claims, stating that he had no part whatsoever. He left his post in 1968 due to a shady plot, of which Abraxas Malfoy was believed part, that resulted in his contracting a mysterious illness.