Background
He was the eldest son of the Review John Edward Nassau Molesworth, vicar of Rochdale, Lancashire, by the vicar"s first wife. William was born 8 November 1816, at Millbrook, near Southampton, where his father then held a curacy.
He was ordained in 1839, and became curate to his father at Rochdale, but in 1841 the wardens and fellows of the Manchester Collegiate Church presented him to the incumbency of Saint Andrew"s Church, Travis Street, Ancoats, in Manchester, and in 1844 his father presented him to the church of Saint Clement, Spotland, near Rochdale, which living he held till his resignation through ill-health in 1889.