 Complete the following phrase:  On 5 April 1755, His Majestys Marine Forces, fifty Companies in three Divisions, headquartered at Chatham, Portsmouth, and Plymouth, were formed by Order of Council under Admiralty control. Initially all field officers were Royal Navy officers as the Royal Navy felt that the ranks of Marine field officers were largely honorary. This meant that the furthest a Marine officer could advance was to lieutet colonel. It was not until 1771 that the first Marine was promoted to colonel. This attitude persisted well into the 1800s. During the rest of the 18th century, they served in numerous landings all over the world, the most famous being the 