Complex sentence: He received his early education at a Quaker school in Ballitore, County Kildare, some from Dublin, and remained in correspondence with his schoolmate Mary Leadbeater, the daughter of the school's owner, throughout his life.
Split into simpler sentences: He received his early education at a Quaker school in Ballitore, County Kildare, some from Dublin. He remained in correspondence with his schoolmate from there, Mary Leadbeater, the daughter of the school's owner, throughout his life.