Complex sentence: When Sebastian Cabot became ill, Giles' brother, Nigel "Niles" French (John Williams) was introduced, working for the Davis family for nine episodes in 1967 while Giles is said to be touring with the Queen in the Commonwealth countries.
Split into simpler sentences: When Sebastian Cabot became ill, Giles' brother, Nigel "Niles" French (John Williams) was introduced. He worked for the Davis family for nine episodes in 1967, while Giles was said to be touring with the Queen in the Commonwealth countries.