In a fascinating history dating back thousands of years, the city of Sofia has been home to a wide variety of peoples. Every single one of the ethnic groups from the past has left traces of their occupation, so the 1.4 million inhabitants of the Bulgarian capital are accustomed to diversity and a broad mix of cultures. However, whenever CSKA and Levski meet to determine the local football bragging rights, you would think the beautiful game was the chief cultural factor influencing the city, fiercely divided in its loyalties but somehow united by a passion for the sport.

It is the clash between the most popular and successful clubs in the country. The local media gushes with superlatives when 26-time champions Levski face-off with 31-time league winners CSKA. The otherwise bustling streets seem to empty for an hour and a half, and certain commentators hail the game as the biggest derby in the whole of the Balkans. The long-term significance of the clash and the intensity of the rivalry between the clubs has earned the fixture a truly awe-inspiring moniker, the Eternal Derby.

The sides clash again in the Bulgarian A-League this Friday in what will be the 174th Sofia derby. Levski have much the better head-to-head record with 77 wins to CSKA's 51, but the current situation in the standings suggests the latter could make up ground. Ten games into the campaign, Levski are four points adrift of cup holders CSKA, currently joint-top with promoted Ludogorets. FIFA.com delves further into the history and stories behind this classic match.

The origins
The intense rivalry between the clubs traces its origins back to the late 1940s. Newly-formed CSKA claimed a maiden championship in 1948, their very first year of existence. In the next two seasons, the new giants of the game beat Levski in replays to win the Soviet Army Cup, following draws in the first match on both occasions. That explosive start to the rivalry split Bulgarian footballing loyalties down the middle, sparking passionate and incident-filled matches year after year. Indeed, the derby bears an unfortunate history of trouble flaring up on the terraces in response to emotion-laden events on the field.

In the course of the following decades, CSKA and Levski both amassed trophies and fans in huge numbers. CSKA, founded as the top-level army sports club, attracted the city's intellectual elite. Levski, named after Bulgarian revolutionary hero Vasil Levski, largely drew support from the suburbs and working-class districts of the city. That has all changed nowadays, when every social class is represented in both the ‘red’ CSKA and ‘blue’ Levski fan bases.

Facts and figures
For many years, the Eternal Derby of Sofia took place on neutral territory, generally the Vasil Levski National Stadium. Around a decade ago, the decision was taken to shift the match to the clubs’ respective home grounds, the Georgi Asparuhiv stadium and the Balgarska Armiva stadium. That decision was soon reversed, simply due to the greater spectator capacity offered by the National Stadium. A match between Levski and CSKA took place outside the capital just once, the Blues defeating the Reds 2-0 to win the Bulgarian cup in Yambol back in 1991.

The record winning-margin was set by Levski in September 1994 with a crushing 7-1 thrashing of their rivals, at least partially avenging 5-0 defeats to CSKA in September 1959 and October 1989. The man with the most derby appearances is CSKA legend Manol Manolov on 35, whereas the top scorer is a Levski idol, 15-goal Georgi Ivanov.

The rivalry today
A review of the last 16 head-to-heads in the Bulgarian top flight simply confirms how little there is to choose between two evenly-matched teams. Levski just about lead the way with six victories to four defeats, and a total of 15 goals scored to their opponents’ 14.

The two clubs have practically taken turns to claim silverware down the years and, with that trend likely to continue, the bitter rivalry shows no sign of abating. However, even the implacable foes can agree on one thing: the last two league titles both went to Litex Lovech, an unfancied side not based in Sofia, so both the Reds and the Blues are utterly determined to bring the trophy back to the capital this term.