Dictatorship finally ended in Portugal, Spain, and Greece, all within the same two years roughly. And also Cyprus had a coup and was invaded and partitioned by Turkey at this time as well. Portuguese colonial rule in Africa and Asia also ended at this time, because of the revolution.
Is there a reason all these events coincided together? I understand the connection between Greek and Cypriot events at the time. But nothing else that happened seems to be obviously linked.
Portuguese and Spanish events were also kinda linked. Of course Franco's death in 1975 was a coincidence, he could've died in 78 or 71, and who knows what would've happened then. The fact that he died in November 75 (and was with one foot in the grave during most of the previous year), very recently after the Carnation Revolution in Portugal, convinced most of the Francoist apparatus (specially members of the Civil Service) as well as the future King Juan Carlos that keeping a dictatorship would be futile and going against public opinion and European geopolitics. This is why there was not much protesting from Franco's apparatus during the transition to democracy, apart from the most ultra right-wing reactionaries, known as the bunker.