PFC Botev Plovdiv is known as "Bultras". Botev's eternal rival is the neighbouring city club of Lokomotiv Plovdiv, and both form the local Plovdiv derby. The two teams are the most supported ones in the second largest city in Bulgaria – Plovdiv – and the matches between them are well known to the Bulgarian football community, and also considered to be one of the fiercest rivalries in the world. Botev is the country's oldest continuously existing team, whereas Lokomotiv grew popular fanbase in the 70s. Traditionally, Lokomotiv's team drew support from the lower working class of society, whereas Botev's fanbase consisted mainly of
PFC Lokomotiv Plovdiv can be defined as that of "Sportclub Plovdiv" (being the fan-based team), and of club of the railway workers (being the team funded by the union). In the spring of 1922 the sport club "Karadzha" is founded administratively by the consolidation of some casual football teams in one of the districts of the city of Plovdiv so that the players can compete in the Championship of Plovdiv. Two years later, in 1924, the sport club "Atletik" is formed in the same district of Plovdiv as Karadzha. On 26 July 1926 the two sport clubs from the same district, Karadzha and