triggered by Vietnam's absorption of Cambodia and the demotion of the Khmer monarchs. Siam seized the opportunity to intervene as the tide of Khmer discontent rose against Vietnamese rule. Siam King Rama III ruled Siam during the 1840s under the Chakri dynasty in Bangkok. Vietnam Emperors Minh Mạng, Thiệu Trị and Tự Đức ruled Vietnam during the 1840s under the Nguyễn dynasty. New Guinea 1848 – British, Dutch, and German governments lay claim to New Guinea. Australia and New Zealand First signing of the Treaty of Waitangi (Te Tiriti o Waitangi) on February 6, 1840, at Waitangi, Northland, New Zealand. The treaty between the British Crown and Māori made New Zealand a colony and is considered the founding point of modern New Zealand. July 20, 1845 – Charles Sturt enters the Simpson Desert in central Australia. May 25, 1846 – The Royal Geographical Society awards Paweł Edmund Strzelecki a Founder's Medal "for exploration in the south eastern portion of Australia". June 15, 1846 – Launceston Church Grammar School opens for the first time in Tasmania. Southern Asia Afghanistan The First Anglo-Afghan War had started in 1838, started by the British as a means of defending India (under British control at the time) from the Russian Empire's expansion into Central Asia. The British attempted to impose a puppet regime on Afghanistan under Shuja Shah, but the regime was short lived and proved unsustainable without British military support. By 1842, mobs were attacking the British on the streets of Kabul and the British garrison was forced to abandon the city due to constant civilian attacks. During the retreat from Kabul, the British army of approximately 4,500 troops (of which only 690 were European) and 12,000 camp followers was subjected to a series of attacks by Afghan warriors. All of the British soldiers were killed except for one and he and a few surviving Indian soldiers made it to the fort at Jalalabad shortly after. After the Battle of Kabul (1842), Britain placed Dost Mohammad Khan back into power (1842–1863) and withdrew from Afghanistan. India March 24, 1843 – Battle of Hyderabad: The Bombay Army led by Major General Sir Charles Napier defeats the Talpur Emirs, securing Sindh as a Province of British India. Sikh Empire The Sikh Empire was founded in 1799, ruled by Ranjit Singh. When Singh died in 1839, the Sikh Empire began to fall into disorder. There was a