During the nineteenth century, the port of Hobart Town was a vital re-supply stop for international shipping and trade, and therefore a major freight hub for the British Empire.

[1] Prior to Australian Federation, the island of Tasmania was a colony of the British Empire, and as such was often at war with Britain's enemies and European rivals, such as France and later Russia.

It was an island, cut off from the mainland of Australia and isolated geographically, making it ideal for a penal colony, and was rich in timber, a resource useful to the Royal Navy.

[2] In 1803, the British authorities decided to colonise Tasmania, and to establish a permanent settlement on the island that was at the time known as Van Diemen's Land, primarily to prevent the French from doing so.

[3] The first permanent British settlement in Van Diemen's Land had begun on 8 September 1803, at Risdon Cove on the Derwent River's eastern shore.

However, the arrival of Lieutenant-Governor David Collins on 16 February 1804, saw him make the decision to relocate the settlement to Sullivans Cove on the western shore of the Derwent River.

[2] A crude earthwork redoubt was dug into an elevated position near the centre of Sullivan's Cove, in the area that is now Franklin Square, and two ships cannons were placed inside.

[4] When Governor Lachlan Macquarie toured the Hobart Town settlement in 1811, he was alarmed at the poor state of the defences and the general disorganisation of the colony.

[2] Following his advice, a new location comprising an area of 8 acres (32,000 m2) was selected at the eastern end of Battery Point on the southern side of Sullivan's Cove, and construction began on what was to become the first of a series of new defensive installations.

The same year, the galleries were improved with large 15 metre long sections of timber, heavy bolts, braces and bars.

One of these contingents was a commander of the Royal Engineers named Captain Roger Kelsall, who arrived in Hobart in 1835 to take over HM Ordnance Department.

He envisaged the forts all having an interlocking firing arc, which would cover the entire approach to Sullivan's Cove, making it impossible for ships to enter the docks or attack the town unchallenged.

[8] This meant that the cost was too prohibitive, considering that at that period the British Empire enjoyed relative peace with the exception of border conflicts in India.

That year ten new 8-inch (200 mm) muzzle loading cannons were lifted into position, enhancing the firepower of the colony's defences.

[citation needed] As a result of these calls, the Tasmanian colonial government began to establish Volunteer Local Militia Forces.

(Wiltshire) Regiment, who began to assume responsibility for the Hobart fortifications from the Royal Artillery who were increasingly being withdrawn, and had all departed well before the withdrawal of the last British forces from Tasmania in 1870.

In 1882, the sites were handed over to Hobart City Council for use as public space, although the subterranean Prince of Wales magazine remains.

[15] As part of Major Roger Kellsall's recommendations, another site to the north-eastern side of Hobart Town was to be used for an additional fortification.

It had been envisaged that this would be the grandest of the forts in Hobart, and would command the prominent point overlooking the entrance to Sullivans Cove; however, the full plans were never developed.

It was decided the current system was inadequate to cope with advances in naval ordnance, and two new forts would be positioned at One Tree Point and Bellerive Bluff.

[citation needed] As the Royal Artillery were to withdraw within two years, a handbook containing range tables was created by Staff-Sergeant R.H. Eccleston which suggested that to repel a vessel doing 10 knots (19 km/h) up the river would take 226 men approximately 30 minutes to fire 365 rounds from the 20 guns that were available from the existing three forts.

[citation needed] Following the condemnation of the Mulgrave, Prince of Wales, and Albert batteries in 1878, it was decided to re-institute the plans for the alteration of the defensive strategy around the entrance to Sullivans Cove that were first drawn up in 1868.

Later that year, a dry mound, and deepened wet moat were added, as was further coarse-work covered in broken bottle glass set in mortar.

[citation needed] With the outbreak of World War II, the Department of Defence acquired land near South Arm close to the mouth of the Derwent River on the eastern shore, from Courtland Calvert and his sister in September 1939.

[1] By the end of 1939, construction of two fortified six-inch (152 mm) Mk VII gun emplacements, and a small four room weatherboard control building had been completed.

[1] Fort Nelson was an artillery battery built on top of Porter Hill circa 1904, offering commanding views of the Derwent Estuary.