Who Claimed Australia in 1770? Great Britain (Captain James Cook)

On 22 August 1770, Captain James Cook of the Royal Navy, commanding HMS Endeavour, landed on Possession Island in the Torres Strait and claimed the entire eastern coast of Australia for Great Britain, naming it New South Wales.

Context

• Not the first European: Dutch (Janszoon 1606, Hartog 1616, Tasman 1642), Portuguese, and possibly others had sighted/landed on western/northern coasts earlier.
• First detailed east coast charting: Cook mapped 3,200 km of coastline, enabling future settlement.
• Legal basis: Claim made under the doctrine of terra nullius (land belonging to no one), ignoring Indigenous sovereignty—later overturned by Mabo decision (1992).
• First Fleet: 18 years later (1788), Britain established the penal colony at Sydney Cove, effectuating the claim.

Thus, the United Kingdom (Great Britain) is the country that formally claimed eastern Australia in 1770 via Cook's expedition.