Complex sentence: However, Byron departed St. Lucia in order to provide escort services to British merchant ships on their way to Europe, so d'Estaing seized the opportunity to begin a series of operations against nearby British possessions.
Split into simpler sentences: However, Byron departed St. Lucia in order to provide escort services to British merchant ships on their way to Europe. D'Estaing seized this opportunity to begin a series of operations against nearby British possessions.