William Bury Homan Mulock was born on 19 April 1841 to Frances Sophia Berry and Thomas Homan Mulock. Educated in Trinity College and was appointed to the Indian Civil Service in 1862.
He served in Bombay in various roles, including Assistant-Registrar of High Court and later Assistant-Magistrate and Collector, 1862-1873; Assistant-Commissioner and Branch Inspector-General of Assurance, and Inspector of Education in Sind, 1873-1876; Collector and Magistrate, 1880; Senior Collector and Magistrate, 1885. In 1885 he chaired the Commission appointed to consider the workings of the factories in the Bombay Presidency. He retired from the Indian Civil Service in 1889 on succeeding to the family estates under his father’s will. He took possession of Bellair House in 1889, and in retirement he served as Justice of the Peace and Deputy Lieutenant for King’s County, as well as JP for County Westmeath. In 1895 he served as High Sheriff for the King’s County.
He died in 1921 and bequeathed Bellair House to his niece, Lady Hester Nina Homan Mulock, who refused to accept it, and handed it to her niece Sheila Claude Beddington Wingfield, Viscountess Powerscourt.