The well-known Oberwolfach problem is to show that it is possible to 2-factorize K n (n odd) or K n less a 1-factor (n even) into predetermined 2-factors, all isomorphic to each other; a few exceptional cases where it is not possible are known. A completely new technique is introduced that enables it to be shown that there is a solution when each 2-factor consists of k r-cycles and one (n − kr)-cycle for all n > 6kr − 1. Solutions are also given (with three exceptions) for all possible values of n when there is one r-cycle, 3 6 r 6 9, and one (n − r)-cycle, or when there are two r-cycles, 3 6 r 6 4, and one (n − 2r)-cycle.