Complex sentence: Though he was never chairman, Joseph was the "dominant influence" at the club after the death of his brother in 1912 with his son, Joe, and grandson, Brian, both later serving as chairman of the football club.
Split into simpler sentences: Though he was never chairman, he was the "dominant influence" at the club after the death of his brother in 1912. Joseph's son, Joe, and grandson, Brian, both went on to be chairman of the football club.