the backs of great birds, believing the European ship's sails looked like seagull wings. However, tension grew quickly amongst the Nuenonne as they realised the Europeans were intending to establish a permanent settlement. By the 1820s, the expansion of European settlements throughout the island, and massive growth in pastoralism came at the expense of the Aborigines, who began to resist the intruders. Clashes became more frequent, and tit-for-tat killings became common. Although exact numbers for the death toll were not recorded, estimates vary between 5–9,000. Towards the end of the 1820s the conflict had become so bad that martial law was declared, and the conflict soon grew into the Black War. By 1831, there were only 200 natives left. Governor George Arthur's attempts to capture and resettle them failed with his disastrous "Black Line" policy. George Augustus Robinson's efforts to resettle them at Flinders Island resulted in the extermination of all the full-blooded native peoples by introduced European diseases such as smallpox, influenza and pneumonia. By 1847 there were only 44 native Tasmanians left, and the last full-blooded Aborigine, Trugannini, died in 1876. Today their race primarily survives in mixed-blood descendants of the women enslaved by Bass Strait whalers and sealers. The expansion and urbanisation of Hobart has destroyed much of the archaeological evidence of prior indigenous occupation, although Aboriginal middens are often still present in coastal areas. As a result, it is difficult for archaeologists and anthropologists to gain a full understanding of the way of life of the Tasmanian Aborigines prior to European settlement. European exploration The Dutch crew of Abel Janszoon Tasman aboard Heemskirk and Zeehaen was the first group of Europeans to sight Tasmania. Leaving the Dutch colony of Batavia in Java (now Jakarta, Indonesia) in August 1642, they charted the Tasmanian coastline in November 1642 (though they did not determine that it was an island), and named it Van Diemen's Land, in honour of the Dutch governor of the Dutch East Indies, Anthony van Diemen. Although the ship did not contact the indigenous Tasmanians at this time, the sighting of the Dutch ships may have led to the creation of myths about spirits riding on great seabirds amongst the Tasmanians. The next visit to the River Derwent was by the Frenchman Marion du Fresne who arrived in 1773 with the ships Mascarin and Castries. As French and British rivalries grew towards the end of the