Though he is most famous as the father of screen actor and director Mel Gibson, this New York-born, Illinois-raised man also fought in World War II, wrote Catholic-themed articles and was a 1968 Jeopardy! champion.
After briefly training for the priesthood, he worked for Western Union. He went on to serve in the Pacific Theater of World War II.
He became well known for his outspoken support of various conspiracy theories.
His first marriage, to Irishwoman Anne Reilly, resulted in ten biological children (including Mel Gibson) and one adopted child. Following his first wife's death, he married Teddy Joye Hicks; they divorced in 2013.
His mother (and Mel Gibson's grandmother), Eva Mylott, was a famous contralto opera singer from Australia.