 The rift between Orson Welles (qv) and Peter Sellers (qv) was  partly caused by the arrival on set of Princess Margaret (qv),  sister of the Queen. Sellers knew her of old and greeted her in an  ostentatious manner to ensure all cast and crew noticed. However,  the Princess walked straight past him and made a big fuss over  Welles. Nonplussed, Sellers stormed off the set and refused to film  with Welles again.