The European Tour (currently known as the DP World Tour for sponsorship reasons), legally the PGA European Tour is the leading men's professional golf tour in Europe. The organisation also operates the European Senior Tour (for players aged fifty or older) and the developmental Challenge Tour; the second tier of men’s professional golf in Europe. The tour's headquarters are at the Wentworth Club in Virginia Water, Surrey, England. The European Tour was established by the British-based Professional Golfers' Association through the 1970s, and responsibility was transferred to an independent PGA European Tour organisation in 1984. Most tournaments on the PGA European Tour's three tours are held in Europe, but starting in the 1980s an increasing number have been held in other parts of the world; in 2015 a majority of the ranking events on the European Tour were held outside Europe, though this included both Majors and World Golf Championship events that are ranking events for multiple tours. Europe-based events are nearly all played in Western Europe, with the most lucrative of them taking place in the United Kingdom, Ireland, Germany, France and Spain. The PGA European Tour is a golfer-controlled organisation whose primary purpose is to maximise the income of tournament golfers. It is a company limited by guarantee and is run by a professional staff but controlled by its playing members via a board of directors composed of 12 elected past and present tour players and a tournament committee of 14 current players. The chairman of the board is David Williams who replaced Neil Coles who had held the post for 38 years. The chairman of the tournament committee is Thomas Bjørn. The PGA European Tour is the lead partner in Ryder Cup Europe, a joint venture also including the PGA of Great Britain and Ireland and PGA of Europe that operates the Ryder Cup Matches in cooperation with the PGA of America. The PGA European Tour has a 60% interest in Ryder Cup Europe, with each of its junior partners holding 20%.