Phillip was unable to follow his original intention of returning to Port Jackson once his health was restored, as medical advice compelled him to resign formally on 23 July 1793. Military personnel in colony The main challenge for order and harmony in the settlement came not from the convicts secured there on terms of good behaviour, but from the attitude of officers from the New South Wales Marine Corps. As Commander in Chief, Phillip was in command of both the naval and marine forces; his naval officers readily obeyed his commands, but a measure of co-operation from the marine officers ran against their tradition. Major Robert Ross and his officers (with the exception of a few such as David Collins, Watkin Tench, and William Dawes) refused to do anything other than guard duty, claiming that they were neither gaolers, supervisors, nor policemen. Four companies of marines, consisting of 160 privates with 52 officers and NCO's, accompanied the First Fleet to Botany Bay. In addition, there were 34 officers and men serving in the Ship's Complement of Marines aboard Sirius and Supply, bringing the total to 246 who departed England. Ross supported and encouraged his fellow officers in their conflicts with Phillip, engaged in clashes of his own, and complained of the governor's actions to the Home Office. Phillip, more placid and forbearing in temperament, was anxious in the interests of the community as a whole to avoid friction between the civil and military authorities. Though firm in his attitude, he endeavoured to placate Ross, but to little effect. In the end, he solved the problem by ordering Ross to Norfolk Island on 5 March 1790 to replace the commandant there. Beginning with guards arriving with the Second and Third fleets, but officially with the arrival of on 22 September 1791, the New South Wales Marines were relieved by a newly formed British Army regiment of foot, the New South Wales Corps. On 18 December 1791, Gorgon left Port Jackson, taking home the larger part of the still-serving New South Wales Marines. There remained in New South Wales a company of active marines serving under Captain George Johnston, who had been Phillip's aide-de-camp, that transferred to the New South Wales Corps. Also remaining in the colony were discharged marines, many of whom became settlers. The official departure of the last serving marines from the colony was in December 1792, with Governor