Information:  - The River Thames is a river that flows through southern England. At , it is the longest river entirely in England and the second longest in the United Kingdom, after the River Severn. It also flows through Oxford (where it is called Isis), Reading, Henley-on-Thames and Windsor. The lower reaches of the river are called the Tideway, derived from its long tidal reach up to Teddington Lock. It rises at Thames Head in Gloucestershire, and flows into the North Sea via the Thames Estuary. The Thames drains the whole of Greater London.   - The 1999 Skol World Darts Championship was held between 28 December 1998 and 3 January 1999 at the Circus Tavern in Purfleet , Essex . After five years , organisers the Professional Darts Corporation scrapped the group stages and the tournament became a straight knock - out for the first time . The third - place play - off which had been a feature for the previous two years was also abandoned . The field was expanded from 24 to 32 players - the biggest influx of players since the PDC separated from the British Darts Organisation in 1992/93 . Phil Taylor emerged as champion for the fifth successive year , taking his overall tally to seven World Championships . He had now eclipsed both Eric Bristow , who won five World Darts titles and Steve Davis and ( at the time ) Stephen Hendry six times World Snooker champions - both targets of Taylor when he began accumulating world championships .  - Barry Maurice William Hearn (born 19 June 1948) is an English sporting events promoter and the founder and chairman of promotions company Matchroom Sport.  - The M25 or London Orbital Motorway is a motorway that encircles almost all of Greater London, England (with the exception of North Ockendon), in the United Kingdom. An ambitious concept to build four concentric ring roads around London was first mooted in the 1960s. A few sections of the outer two rings were constructed in the early 1970s, but the plan was abandoned and the sections were later integrated to form a single ring which became the M25 and was finally completed in 1986.  - Purfleet is a town in the Thurrock unitary authority in Essex, England. It is contained between the A13 road to the north and the River Thames to the south and is within the easterly bounds of the M25 motorway but just outside the Greater London boundary. It was within the traditional Church of England parish of West Thurrock. There is some industry to the south and the area forms part of the Thames Gateway redevelopment area. Purfleet is one of seven conservation areas in Thurrock.  - The Circus Tavern is an entertainment venue in Purfleet, Essex, England which hosts functions, cabaret acts and is also a nightclub venue. However, it is most famous as having been a long-time venue of the PDC World Darts Championship.  - The Thames Gateway is an area of land stretching east from inner east London on both sides of the River Thames and the Thames Estuary. The area, which includes much brownfield land was designated during the early years of the Blair ministry a national priority for urban regeneration, taking advantage of the development opportunities realised by the completion of the High Speed 1 (officially known as the Channel Tunnel Rail Link). First named by the UK government, which is unusual in the United Kingdom, uptake of and appreciation of the term varies, with many people preferring the traditional term, the Thames Estuary.  - The PDC World Darts Championship, organised by the Professional Darts Corporation (PDC), is one of the two World Professional Darts Championships held annually in the sport of darts. The other is the BDO World Darts Championship organised by the British Darts Organisation (BDO). The PDC championship begins in December, overlapping in January with the start of the BDO tournament. The highest profile of the PDC's tournaments, it is held at Alexandra Palace in London and is sponsored by bookmaker William Hill; winners receive the Sid Waddell Trophy, named in honour of the legendary darts commentator Sid Waddell, who died in 2012.  - Thurrock is a unitary authority area with borough status in the English ceremonial county of Essex. It is part of the London commuter belt and an area of regeneration within the Thames Gateway redevelopment zone. The local authority is Thurrock Council.  - The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a sovereign country in western Europe. Lying off the north-western coast of the European mainland, it includes the island of Great Britain (the name of which is also loosely applied to the whole country), the north-eastern part of the island of Ireland, and many smaller islands. Northern Ireland is the only part of the UK that shares a land border with another sovereign statethe Republic of Ireland. Apart from this land border, the UK is surrounded by the Atlantic Ocean, with the North Sea to its east, the English Channel to its south and the Celtic Sea to its south-south-west, giving it the 12th-longest coastline in the world. The Irish Sea lies between Great Britain and Ireland. With an area of , the UK is the 78th-largest sovereign state in the world and the 11th-largest in Europe. It is also the 21st-most populous country, with an estimated 65.1 million inhabitants. Together, this makes it the fourth most densely populated country in the European Union.  - The British Darts Organisation (BDO) is a darts organisation founded on 7 January 1973 by Olly Croft, OBE. The BDO is a founder member of the World Darts Federation which was formed in 1976. The BDO comprises 66 member counties in Britain and organises tournaments for amateurs.  - The Church of England (C of E) is the Anglican Christian state church of England. Headed by the Archbishop of Canterbury (currently Justin Welby) and primarily governed from London with the monarch as the supreme governor, the Church of England is also the mother church of the international Anglican Communion. The church dates its formal establishment as a national church to the 6th-century Gregorian mission in Kent led by Augustine of Canterbury, with considerable features introduced and established during and following the English Reformation in the 16th century.  - Darts is a form of throwing sport in which small missiles are thrown at a circular dartboard fixed to a wall. Though various boards and rules have been used in the past, the term "darts" usually now refers to a standardised game involving a specific board design and set of rules. As well as being a professional competitive sport, darts is a traditional pub game, commonly played in Britain and Ireland, across the Commonwealth, the Netherlands, Germany, the Scandinavian countries, the United States, and elsewhere.  - The Professional Darts Corporation (PDC) is a professional darts organisation in the United Kingdom, established in 1992 when a group of leading players split from the British Darts Organisation to form what was initially called the World Darts Council (WDC). Sports promoter Barry Hearn is the PDC chairman.  - The World Darts Federation (WDF) is the official world sport governing body and tournament organisers and (one of two) for the game of darts. It was formed in 1974, by representatives of the original fifteen founding members. Membership is open to the national organizing body for darts in all nations. The WDF encourages the promotion of the sport of darts among and between those bodies, in an effort to gain international recognition for darts as a major sport. The WDF is a full member of SportAccord, which is the governing body for international sports federations.  - West Thurrock is a traditional Church of England parish and town in Thurrock, Essex, England, located 17.5 miles (28.1 km) east south-east of Charing Cross, London.  - England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west. The Irish Sea lies northwest of England and the Celtic Sea lies to the southwest. England is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain (which lies in the North Atlantic) in its centre and south; and includes over 100 smaller islands such as the Isles of Scilly, and the Isle of Wight.  - Oliver Albert "Olly" Croft, (born 17 November 1929) is a former darts administrator and the founder of the British Darts Organisation. He was one of the most influential protagonists in darts for almost four decades having set up and run the British Darts Organisation from its inception in 1973 until he was voted off the board in August 2011.    Given the information, choose the subject and object entities that have the relation of 'instance of'.
The answer to this question is:
1999 skol world darts championship , pdc world darts championship