Complex sentence: Later the two corresponded in the early 1950s and met around 1958, after Handley's term in the Armed Forces and attendance at Balliol College, Oxford, he became Boult's pupil.
Split into simpler sentences: Later the two corresponded in the early 1950s and met around 1958. After Handley's term in the Armed Forces and attendance at Balliol College, Oxford, he became Boult's pupil.