sentences:  From 1970 to 1974, Hayes was director of the London Museum, overseeing its move to new premises on London Wall.In 1974 he was subsequently appointed director of the National Portrait Gallery, succeeding Sir Roy Strong in the post.The duties that came with the NPG directorship did not curtail Hayes's scholarly activities, however, and during his tenure he managed to curate a major Gainsborough exhibition at the Tate and the Grand Palais, Paris), and numerous smaller ones, including one of Graham Sutherland's work.