William Light (27 April 1786 – 6 October 1839), also known as Colonel Light, was a British-Malayan naval and army officer. He was the first Surveyor-General of the new British Province of South Australia, known for choosing the site of the colony's capital, Adelaide, and for designing the layout of its streets, six city squares, gardens and the figure-eight Adelaide Park Lands, in a plan later sometimes referred to as Light's Vision.
He was the eldest son of Captain Francis Light, founder of Penang, and Martina Rozells.
At the age of 13 in about 1799, Light volunteered for the Royal Navy, in which he served for two years, leaving as a midshipman.
After a spell as a civilian internee in France in 1803–04, he attended his sister Mary's wedding to indigo plantation owner George Boyd in Calcutta in March 1805, remaining in India until November 1806, before returning to Europe. He bought a cornetcy in the 4th Dragoons regiment of the British Army on 5 May 1808, being promoted to lieutenant in April 1809 en route to Spain to serve in the Peninsular War, where he learnt Spanish. After courageous service against Napoleon's forces from 1809 to 1814, he served under the Duke of Wellington working on mapping, reconnaissance and liaison. He showed both outstanding bravery and kindness in his actions, and was a favourite of Wellingon. He went on to serve in the infantry in various parts of Britain – the Channel Islands, Scotland and Ireland – as a captain, after purchasing the rank in November 1814.
After quitting the army with the brevet rank of major, Light married Miss E. Perois in Derry, Ireland, on 24 May 1821, and moved in literary and artistic circles in Paris, Italy and Sicily for a couple of years. However, his young wife died sometime during those years.
In 1823 he returned to Spain to fight the French invasion as aide-de-camp to Sir Robert Wilson, who had raised an international (mostly French) force to help the "Liberales" in their constitutional struggle against King Ferdinand VII. Originally volunteering as a private in the Vigo militia, Light was made a lieutenant-colonel. He was badly wounded at Corunna in Spain.
By 1835, negotiations had been completed for the founding of the new British Province of South Australia, according to the scheme of Edward Gibbon Wakefield, intended as a self-supporting free colony.
Light had given Hindmarsh a letter of introduction to Colonel Charles James Napier, who was the recently designated Governor of the new colony. However, Napier was not interested in the position, and upon hearing this, Hindmarsh rushed to London and lobbied for the position, after seeing Napier in Portsmouth in May 1835. Napier recommended to the authorities that Light be given the post of Governor, but Hindmarsh had already been promised it. Light returned to London in January 1836, and on 4 February was appointed Surveyor-General of South Australia instead.
On 1 May 1836 Light sailed for South Australia with Maria Gandy, two of her young brothers William and Edward, and some of his survey staff, on the survey brig, Rapid, along with the nine other ships in the "First Fleet". The ship reached Kangaroo Island on 17 August 1836. Sailing from Nepean Bay on 23 September, Light started exploring Gulf St Vincent, sailing first past Rapid Bay, then up to Port Adelaide before returning to Rapid Bay. In the meantime Cygnet had arrived at Nepean Bay, Kangaroo Island, with the assistant surveyors. Soon afterwards Africaine arrived, with Colonial Secretary Robert Gouger and other colonial officers anxious to know where the settlement should be situated. Light suggested that the ships land at Holdfast Bay for the meantime, while he went with a group to explore further. The group encountered a group of Indigenous Australians for the first time at Rapid Bay (belonging to one of the Ramindjeri tribes) and was reported to have established a friendly and cooperative relationship with them. After finding the Port River, Light then sailed across to Port Lincoln, on Spencer's Gulf, but found the area unsuitable. In addition to lack of surface water, Light found navigation of Spencer's Gulf and southern entry into Boston Bay more hazardous. On 18 December he decided on the site of Adelaide for the new capital, and headed north to survey the coast 8 mi (13 km) north with a view to its being the site for a harbour. HMS Buffalo arrived at Holdfast Bay on 28 December. That same day Governor Hindmarsh landed and, all pre-requisites having been met, proclaimed the commencement of colonial government (henceforth celebrated as Proclamation Day).