Complex sentence: After the war, he became an acting full-time secretary to the Leeds branch of the Communist Party from 1946 to 1953, where he encouraged political activism within Yorkshire mining community working with the National Union of Mineworkers where he mentored a young Arthur Scargill.
Split into simpler sentences: After the war, he became an acting full-time secretary to the Leeds branch of the Communist Party. He held this post from 1946 to 1953 and encouraged political activism within Yorkshire mining community working with the National Union of Mineworkers where he mentored a young Arthur Scargill.