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 prestigious tournaments. By 1944 the team is the biggest in the region of Plovdiv in terms of members, and has a dedicated following with its fans setting records for the period in attendance of football matches. In the mid-1930s the labour union of the railway workers and sailors establishes several cultural and sporting organisations across the country. The railway workers established their sports club in Plovdiv as well, since the city is one of the major travel centres in the country. On 13 June 1935 the club "ZSK Plovdiv" was founded, abbreviated from "Zheleznicharski Sporten Klub Plovdiv" meaning "the sporting