He represented Ballynakill in the Irish House of Commons and was High Sheriff of Queen's County in 1689.
His son Sir John Fleming Leicester, the fifth Baronet, was Member of Parliament for Yarmouth, Heytesbury and Stockbridge.
His eldest son Sir George Leicester[4] the second Baron, assumed in 1832 by Royal licence the surname of Warren in lieu of Leicester under the terms of the will of his kinswoman Elizabeth Warren-Bulkeley (née Warren), Viscountess Bulkeley.
He sat on the Liberal benches in the House of Lords and served under William Ewart Gladstone as Treasurer of the Household between 1868 and 1872.
When he died in 1895 the barony became extinct while he was succeeded in the baronetcy by his kinsman Peter Fleming Frederic Leicester, the eighth Baronet.