Thomas Homan Mulock was born in 1756, the son of the Rev. John Mulock and Anne Homan. He served as a Justice of the Peace for King’s County before he was appointed High Sherriff of the county in 1822.
In 1803 he married Catherine Frances, daughter of Thomas Berry, of Eglish Castle, and Elizabeth Bury, of Charleville Castle, and a direct descendent of King Edward. They had no children. Thomas demolished the old Bellair House which stood close to the present house. The new Bellair House was designed by Richard Morrison. He was also given permission by his father, the Rev John Mulock, to build 50 slated houses in Bellair to accommodate the workers who were engaged in the Flax and Linen industry.
He made his will dated 18 October 1841, and after making provision for his wife, he devised his estates to his nephew, Thomas Homan Mulock Molloy. He directed his nephew on becoming entitled to the estates to take the sole name and arms of Homan Mulock. He died on 16 January 1843 and was buried at Liss, King’s County