Big Two derby

The term "Big Two" did not always refer to Linfield and Glentoran. Up until 1949, the big two were considered to be Linfield and Belfast Celtic as they had traditionally been the most successful teams in Northern Irish football. Given the traditional political following of both clubs (Linfield, like Glentoran, with a mainly unionist following, and Belfast Celtic with a mainly nationalist following), sectarian violence between supporters of both clubs was common. This culminated with a riot on 26 December 1948 at Windsor Park that saw three Celtic players injured by Linfield supporters, including striker Jimmy Jones who sustained a broken leg.[5] Belfast Celtic left the Irish League at the end of the season and Glentoran became Linfield's biggest rivals.[6]

Both teams are predominantly Protestant; however, Glentoran has fielded Catholic players and had Catholic fans for much of its history. Linfield fielded relatively few Catholic players prior to the 1980s,[7] which led to an accusation that the club held a policy of not signing Catholic players – similar to Scottish team, Rangers.[8] However, the existence of such a policy has been disputed by some, including well-known local journalist Malcolm Brodie.[9] Support is traditionally split geographically with Linfield based in the south of the city and Glentoran in the east. Although both based in Belfast, they are separated by the River Lagan and are in two different counties. Linfield is based in County Antrim and Glentoran is based in County Down, although Glentoran and other County Down-based sides compete in the County Antrim Shield.

The first game of which there is any record between Linfield and Glentoran took place on 1 October 1887. A friendly match played at King's Field, Westbourne in Ballymacarrett was won 3–1 by Linfield (then known as Linfield Athletic), with goalscorers Torrans (2) and Vance, and Glentoran's goalscorer unknown. The two teams played each other competitively for the first time in the inaugural Irish League season, with Linfield winning 7–0 at Musgrave Park on 18 October 1890, and 6–0 at Ulsterville Avenue on 21 March 1891. The first game at The Oval took place on 8 October 1892, and the first game at Windsor Park on 2 September 1905. Linfield previously played at a ground in Ulsterville Avenue, Belfast, before moving to Windsor Park, which is situated within walking distance of their old ground. Also the home of the Northern Ireland national football team, they have played at Windsor Park ever since.

In 1941, during World War II, The Oval – including terraces, offices, kits and club records – was destroyed in a bombing raid on the nearby Harland & Wolff Shipyard. Glentoran approached Distillery to play at Grosvenor Park, which they did until The Oval was rebuilt in 1949, with help from other Irish League clubs, most notably Distillery and Cliftonville. Glentoran considered leaving senior football to become a junior club, but after being lent kits from Distillery and Crusaders they continued to compete at Grosvenor. Out of 14 league games at Grosvenor Park however, they were only victorious over Linfield on one occasion.[10]

Since Belfast Celtic folded in 1949, the intensity of the Big Two rivalry has increased due to the fact that Glentoran has been the only club that has generated a support base similar in size to Linfield's, and because a number of Belfast Celtic fans started to support Glentoran due to the dissolution of their club.[11] In the 1985 Irish Cup final at the Oval, Glentoran supporters released a cockerel (Glentoran's club emblem), and a pig that had been painted blue onto the pitch to insult fans of Linfield.[2] In 2005, Linfield fans broke through a gate in perimeter fencing onto the pitch of The Oval and threw missiles at Glentoran fans in the main stand.[12] The BBC and Ulster Television were ordered to give police footage they had filmed of the game after 9 fans were charged with the violence. 9 police officers and 2 Glentoran fans were injured in the violence.[13]

Both sides share rivalries with North Belfast clubs Cliftonville and Crusaders. The two however are less successful than the Big Two and see each other as their main rivals, contesting the North Belfast derby. They also both traditionally shared a rivalry with Lisburn Distillery, but since Distillery's relocation from Grosvenor Park to Lisburn, and their downturn in on-pitch fortunes, the rivalry has ebbed.

Linfield and Glentoran have been the two most successful clubs in Northern Irish football to date, regularly being the two main contenders for the major domestic honours. They have won more league titles, Irish Cups, and League Cups than any other clubs. Linfield hold the record for the most League titles (54), Irish Cups (43), and League Cups (10). In comparison, Glentoran have won 23 league titles, 23 Irish Cups, and 7 League Cups. Almost half (47.1%) of the 140 Irish Cup competitions to date have been won by one of the two clubs, with at least one of the clubs reaching the final on 91 occasions (65% of all finals), winning the cup a combined 66 times. Of those 91 finals, the two clubs have met in 15 of them – making it the most common final. Linfield have won eight of the head-to-head final meetings compared to Glentoran's seven wins, with the most recent final meeting between the two clubs occurring in the 2006 final, when Linfield won 2–1 to lift the Cup for the 37th time. Almost two-thirds (64.7%) of all Irish League titles have been won by one of the Big Two. Of the 119 completed league seasons, the title has been won by either club on 77 occasions. The duo also make up two of the three clubs that have appeared in every season of the Irish League since its inception in 1890; the other club being Cliftonville.