John Blennerhassett Anglo-Irish politician (1691–1775) Parents Margaret Crosbie John Blennerhassett Children Arabella Blennerhassett Mary Blennerhassett John Blennerhassett Letitia Blennerhassett Arthur Blennerhassett Agnes Blennerhassett Siblings Pierce Blennerhassett Arthur Blennerhassett Agnes Blennerhassett Thomas Blennerhassett William Blennerhassett Robert Blennerhassett