Conversation so far:
Can you provide me with a little information about Walter Winterbottom and his career as an England Team Manager?
Walter Winterbottom was England's first, youngest and longest serving England team manager. He is also the only England manager to have had no previous professional managerial experience.
How long did Walter Winterbottom serve as an England team manager?
Walter Winterbottom served as team manager for England between 1946 and 1962

Question: How old was he when he first began his career as a team manager?
Self-contained rewrite: How old was Walter Winterbottom when he first began his career as a team manager?