The first troops to serve in Australia were four companies of British Marine Corps, who arrived with the first fleet in 1788. 

This detachment consisted of 16 officers, 12 sergeants, 12 corporals, 8 drum and fife and 160 privates, which served mainly as a convict guard. The convicts would have probably revolted if they found out the Marines had actually left their ammunition and musket balls on the docks at Portsmouth. 

Unlike the NSW corps who relieved them, the marines were well disciplined and well behaved during their service, often sharing in the hardships and fears of the first settlers, whilst at the same time never becoming tyrannical or oppressive. 

It was Marine expeditions that led to the opening up of much of the land around Sydney for settlement. 

Many of the marines on the first fleet were former tradesmen displaced by the industrial revolution and they helped build the fledging colony and became the first schoolteachers, armourers, police, ship-builders, and masons etc. 40 women, mostly wives to the marines, were permitted to set sail with the garrison. Some of the marines opted to take convict women for wives and mistresses for the duration of their time in Sydney.