It long remained a small village on the banks of the river, but by the 16th century warships were being moored at Jillingham water (Gillingham), because of its strategic sheltered location between London and the Continent. It was established as a Royal Dockyard by Queen Elizabeth I in 1568 and most of the dockyard actually lies within Gillingham. Initially a refitting base, it became a shipbuilding yard; from then until the late 19th century, further expansion of the yard took place. In its time, many thousands of men were employed at the dockyard, and many hundreds of vessels were launched there, including HMS Victory which was built there in the 1760s. After World War I many submarines were also built in Chatham Dockyard. In addition to the dockyard itself, defensive fortifications were built to protect it from attack. Upnor Castle had been built in 1567, but had proved ineffectual; the Dutch Raid on the Medway in 1667 showed that more was required. The fortifications, which became more elaborate as the threat of invasion grew, were begun in 1756 as a complex across the neck of the peninsula formed by the bend in the River Medway, and included Fort Amherst. The threat of a land-based attack from the south during the 19th century led to the construction of even more forts. The second phase of fort-building (1806-1819) included Fort Pitt (later used as a hospital and the site of the first Army Medical School). The 1859 Royal Commission on the Defence of the United Kingdom ordered, inter alia, a third outer ring of forts: these included Fort Luton, Fort Bridgewood, and Fort Borstal. These fortifications all required military personnel to man them and Army barracks to house those men. These included Kitchener Barracks (c 1750-1780), the Royal Marine Barracks (c 1780), Brompton Artillery Barracks (1806) and Melville Barracks (opened 1820 as a Naval hospital, RM barracks from 1905). H.M.S. Collingwood and H.M.S. Pembroke were both naval barracks.