Being a landlocked country, the history of Bhutan has always been influenced by its geography. The name 'Bhutan' appears to derive from the Sanskrit 'Bhotant' meaning 'the end of Tibet' or from 'Bhu-uttan' meaning 'high land'. Though known as Bhutan to the outside world, the Bhutanese themselves refer to their country as Druk Yul or the Land of the Thunder Dragon. 'Druk' meaning 'Dragon' and it is extending from the predominant Drukpa school of Tibetan Buddhism. The documented history of the Kingdom begins with 747 A.D. with Guru Padmasambhava also known as Guru Rinpoche who made his legendary trip from Tibet across the mountains flying on a tigress's back. He arrived in Paro valley at Taktsang Lhakhang also known as Tiger's Nest. Guru Rinpoche is not only recognized as the founder of the Nyingmapa religious school but also considered to be second Buddha. In the ensuing centuries, many great masters preached the faith resulting in full bloom of Buddhism by the middle ages. Although sectarian at first, the country was eventually unified under Drukpa Kagyupa sect of Mahayana Buddhism by saint/administrator Shabdrung Ngawang Namgyal in the 17th century. Ngawang Namgyal codified a comprehensive system of laws and built a chain of Dzongs which guarded each valley during unsettled times and now serving as the religious and administrative centre of the region. During the next two centuries civil wars intermittently broke out and the regional Governors became increasingly more powerful. At the end of 19th century, Trongsa Governor overcame all his rivals and soon afterwards recognized as the overall leader of Bhutan. The Governor of Trongsa, Sir Ugyen Wangchuck, was elected as the first King of Bhutan in 1907 by an assembly of representatives of the monastic community, civil servants and people. Since then, the country has been ruled by successive monarchs of the Wangchuck dynasty. In November 2001, on the advice of the Fourth king, a committee chaired by the Chief Justice of Bhutan, was formed to draft the constitution of Bhutan. The constitution was launched in 2008 and with it a parliamentary democracy introduced. The progression from hereditary monarchy to that of a Parliamentary Democracy has been a carefully managed process that culminated in 2008 when Bhutan held its first elections country wide. Since 18 July 2008, Bhutan has a two-chamber parliamentary system: The Upper House of parliament, the 25-seat National Council, and the Lower House of Parliament (National Assembly – Tshogdu) with 47 seats. The government is headed by a Prime Minister and the King is still head of state.