Complex sentence: Seed, an ex-miner who had made a career as a footballer despite suffering the effects of poison-gas in the first war, remains the most successful manager in Charlton's history and he is commemorated in the name of a stand at the Valley.
Split into simpler sentences: Seed, an ex-miner who had made a career as a footballer despite suffering the effects of poison gas in the First World War, remains the most successful manager in Charlton's history. He is commemorated in the name of a stand at the Valley.