Complex sentence: From 1963 onward, he served as the head of antiquities in Palmyra for 40 years, retiring in 2003 to become an expert with the antiquities and museums department.
Split into simpler sentences: From 1963 onward, he served as the head of antiquities in Palmyra for 40 years. He retired in 2003 to become an expert with the antiquities and museums department.