Why did the name Michael become popular in the 1940's and 50's

A newspaperman says that names are chosen by the upper class as distinctive and filter down. True maybe and perhaps related with a twist here. I was looking at a list of famous people with the name Michael. Mickey Spillane, born 1918, is included. I believe he is part of the answer, but his first book didn't come out until 1947. He was born Frank Morrison Spillane and chose the pen name Mickey. Mickey Mouse probably played a role, Mickey being a diminutive of Michael; he emerged in the 20's, the timing for an influence is good, and there had been, earlier, Michael Collins, in a way the real father of the Irish Republic, and Michael Sparks an American boxer, 1901-1981, and by the way, welcome aboard Avrom Hirsch Goldbogen who changed his name to Michael Todd and married Elizabeth Taylor.