What was the primary purpose of the First Fleet's voyage?

The primary purpose of the First Fleet's voyage was to establish a British penal colony in Australia to relieve the overcrowded prisons and hulks (prison ships) of Britain. The Fleet was also intended to establish British sovereignty over the eastern half of the Australian continent and to create a foothold for future trade, exploration, and strategic influence in the Pacific.

Several specific factors drove the decision to send convicts to Australia. The American Revolutionary War (1775 to 1783) had ended the practice of transporting British convicts to the American colonies. British prisons and hulks had become severely overcrowded by the mid-1780s. The Beauchamp Committee of the British Parliament investigated alternative locations in 1779 and recommended Botany Bay (on the basis of Joseph Banks' favourable report from Captain Cook's 1770 voyage). The Cabinet decision to send the First Fleet to Botany Bay was made in August 1786.

Strategic considerations also shaped the decision. Establishing a settlement in the south Pacific would secure access to the timber, hemp, and flax of Norfolk Island (then thought to be a strategic supply source for Royal Navy ships). It would provide a base for trade with Asia and the Pacific Islands. It would forestall French claims to the continent (the French expedition under Lapérouse arrived at Botany Bay just days after the First Fleet, underlining the strategic competition). It would extend British influence in the southern hemisphere at a time of growing imperial rivalry.

The voyage had multiple instructions. Phillip was to establish the settlement, grow food for self-sufficiency, establish friendly relations with Aboriginal people, explore the country to assess its potential, set up the Norfolk Island settlement, and send back reports on the new colony. He was also given discretion to make decisions based on conditions encountered, given the impossibility of consulting London during the long voyage. The convict purpose was the dominant initial purpose, but the colony quickly developed into a broader settlement society with free immigrants arriving from 1793 onwards and agricultural, commercial, and cultural development establishing the foundations of what became modern Sydney and the wider Australian colonies.