William Blennerhassett (1801-1860) (1801–1860) Parents Arthur Blennerhassett Dorcas Twiss Children John du Boulay Blennerhassett Emma Sophia Blennerhassett Francis Houssemayne Blennerhassett William Blennerhassett Mary Anne Blennerhassett Arthur Blennerhassett Agnes Blennerhassett Siblings Arthur Blennerhassett John Blennerhassett Partners Emma Sophia Houssemayne Du Boulay