Complex sentence: His studies were disturbed by the invasion of Iberia, during which he served as a sentry in Coimbra and later on h4e accompanied the British Army with Wellington's forces to Lisbon as an interpreter.
Split into simpler sentences: His studies were disturbed by the invasion of Iberia, during which he served as a sentry in Coimbra. Later, he accompanied the British Army with Wellington's forces to Lisbon as an interpreter.