John Waller was the Adjutant of the 1st Battalion of Marines (later the Royal Marines) sent to Boston in the spring of 1775. His detailed account of the Battle of Bunker Hill, an action "very fatal to the 1st Battalion" clearly was written to a friend or fellow officer familiar with the officers of the battalion. After the battle, the 1st Battalion manned a fortification that the British built on Bunker Hill.