Complex sentence: The club went from strength to strength, until the outbreak of World War II. Inevitably playing of all sport was curtailed but a decision by the local authority in connection with the war effort brought mixed blessings to the club.
Split into simpler sentences: The club went from strength to strength, until the outbreak of the Second World War. Inevitably, playing of all sport was curtailed but a decision by the local authority in connection with the war effort brought mixed blessings to the club.