Which Python left the TV series after the third series?

John Cleese left Monty Python's Flying Circus after its third series. He remained part of the original six-member ensemble through series three, but did not return as a regular performer for the fourth and final series.

Cleese's departure reflected growing frustration with the demands and working methods of the television show. He had already considered leaving after series two, and by the end of series three he felt that continuing the same format was becoming difficult. The remaining Pythons carried on without him, creating the six episodes that made up series four in 1974.

The timing can cause confusion because Cleese did not disappear completely from the wider Monty Python story. He continued collaborating with the group on material developed during earlier writing sessions, and he remained central to the troupe's films, including Monty Python and the Holy Grail, released during the television show's run. He also returned for later Python projects and reunions. The other listed names—Michael Palin, Terry Gilliam, and Eric Idle—remained with the television series through its final series.