Complex sentence: Gass was succeeded as Artistic Director of Factory by Bob White (1977--87), then Jackie Maxwell (1987--95), then Michael Springate for one season, 1995-96.
Split into simpler sentences: Gass was succeeded as Artistic Director of Factory by Bob White (1977--87), then Jackie Maxwell (1987--95). English left in 1995 and Michael Springate came on as Artistic Director for one season, 1995-96.