Complex sentence: He was a supporter and friend of Hugh Gaitskell and helped persuade him not to support military action when the Suez Canal was unexpectedly seized by the Nasser regime in Egypt, resulting in the Suez Crisis.
Split into simpler sentences: He was a supporter and friend of Hugh Gaitskell. He helped to persuade Gaitskell not to support military action when the Suez Canal was unexpectedly seized by the Nasser regime in Egypt, resulting in the Suez Crisis.