Conversation so far:
When was Walter Winterbottom FA director of Coaching?
Walter Winterbottom was appointed national director of coaching on 8 July 1946 with responsibility for the national team.
Was Walter Winterbottom successful as national director?
Walter Winterbottom created a credible national coaching scheme with summer residential courses that attracted international participation and praise, and inspired a new generation of managers.
Who were some of the new generation of managersinspired by Walter Winterbottom?
Walter Winterbottom inspired a new generation of managers, most notably Ron Greenwood and Bobby Robson who graduated through every level of coaching, both eventually becoming England team manager.

Question: How long were they with the team?
Self-contained rewrite: How long were Bobby Robson and Ron Greenwood with the england team?