Complex sentence: Lancelot Lionel Ware OBE (5 June 191515 August 2000) was an English barrister and biochemist, but whose main claim to fame is co-founding Mensa, the international society for intellectually gifted people, with the Australian barrister Roland Berrill in 1946.
Split into simpler sentences: Lancelot Lionel Ware OBE (5 June 1915--15 August 2000) was an English barrister, biochemist and co-founder of Mensa. Lancelot Ware's main claim to fame is co-founding Mensa, the international society for intellectually gifted people, with the Australian barrister Roland Berrill in 1946.