[1] Leslie was born in Derry, one of the numerous children of James Leslie, Bishop of Limerick, Ardfert and Aghadoe and Joyce Lyster, and grew up at Tarbert, County Kerry.
Sir Edward Leslie, 1st and last Baronet of Tarbert, was his eldest brother.
[3] As a young clergyman, he seems to have led an unsettled and extravagant lifestyle, and spent some time in a debtors' prison.
In contrast to his rather unsatisfactory early career, he became a conscientious and much-loved pastor during his years in India.
His tomb in Madras Cathedral was sculpted by John Flaxman in London and shipped to India.