Complex sentence: Many of the Palyam members formed the core personnel and command of the Naval Service, in fact, most ship commanders during the first years of the Navy, and up to 1975, most of the Navy's commander-in-chiefs, were Palyam veterans.
Split into simpler sentences: Many of the Palyam members formed the core personnel and command of the Naval Service. In fact, most ship commanders during the first years of the Navy, and up to 1975, most of the Navy's commander-in-chiefs, were Palyam veterans.