In October, 1963, the international crisis that centered on, and arose out of, events on the Caribbean island of Cuba, was the culmination of a series of events which had kept Cuba in the world's headlines for the previous four years — ever since the revolutionary régime headed by Dr. Fidel Castro established itself in power in December, 1958. The understanding of this crisis is quite difficult, because this matter has been subject to widely-differing interpretations, and many aspects of the regime's history are intensely controversial.