the Trucial Coast and the British led to the sacking of Ras Al Khaimah by British forces in 1809 and again in 1819, which resulted in the first of a number of British treaties with the Trucial Rulers in 1820. These treaties, starting with the General Maritime Treaty of 1820, led to peace and prosperity along the coast and supported a lively trade in high quality natural pearls as well as a resurgence in other regional trade. A further treaty of 1892 devolved external relations to the British in return for protectorate status. A British decision, taken in early 1968, to withdraw from its involvement in the Trucial States, led to the decision to found a Federation. This was agreed between two of the most influential Trucial Rulers, Sheikh Zayed bin Sultan Al Nahyan of Abu Dhabi and Sheikh Rashid bin Saeed Al Maktoum of Dubai. The two invited other Trucial Rulers to join the Federation. At one stage it seemed likely Bahrain and Qatar would also join the Union of Arab Emirates, but both eventually decided on independence. Today, the UAE is a modern, oil exporting country with a highly diversified economy, with Dubai in particular developing into a global city and a hub for tourism, retail, and finance, home to the world's tallest building, and largest man-made seaport. Prehistory In 2011 primitive hand-axes, as well as several kinds of scrapers and perforators, were excavated at the Jebel Faya archaeological site in the United Arab Emirates. These tools resemble the types used by early modern humans in East Africa. Through the technique of thermoluminescence dating the artefacts were placed at 125,000 years old. This forms some of the earliest evidence of modern humans found anywhere outside Africa and implies modern humans left Africa much earlier than previously thought. The site of these discoveries has been preserved alongside finds of later cultures, including tombs and other finds from the Hafit, Umm Al Nar, Wadi Suq, Iron Age, Hellenistic and Islamic periods, at Sharjah's Mleiha Archaeological Centre. Glacial period During the glacial maximum period, 68,000 to 8000 BCE, Eastern Arabia is thought to have been uninhabitable. Finds from the Stone Age Arabian Bifacial and Ubaid cultures (including knapped stone arrow and axe heads as well as Ubaid pottery) show human habitation in the area from 5000 to 3100 BCE and define a linkage between the human settlements of the Gulf and