Lokomotiv Plovdiv

Throughout the club's history, it has undergone a number of complex reorganisations. These were in part due to the political environment in Bulgaria during the communist period (1944–1989) which led to enforced changes in the nature of sporting clubs throughout the country in order to follow the "Soviet model". For PFC Lokomotiv Plovdiv, these changes led to the merger of two separate existing teams, different in nature, which in turn has led to misinterpretations of the history of the teams. In order to understand the origin of the contemporary team, Lokomotiv's history can be divided into two major branches – one defined largely by its followers (Sportclub Plovdiv), and the other by its functional characteristics, association with the railway, and funding as a labour union team (ZSK Plovdiv).

Sportclub Plovdiv

In the spring of 1922, the sport club Karadzha was founded when several casual amateur football teams in one of the districts of Plovdiv consolidated so the players could compete in the Championship of Plovdiv. Two years later, in 1924, another sport club called Atletik was formed in the same district.

On 25 July 1926 Karadzha and Atletik merged to form Sportclub. The team chose white, black and red as the colours for their kits and crest. Several years later, the year of establishment (1926) was added to the crest. Lokomotiv Plovdiv still uses the same colours, while their full name (Professional Football Club Lokomotiv 1926 Plovdiv) shows the club's beginnings as the same year in which Sportclub was founded.

Sportclub had its home ground in the city centre. However, after the 1928 earthquakes, the team donated its land to those who had lost their homes so they could rebuild there. From 1928 on, Sportclub did not have their own football field for more than two decades.

In the years after Sportclub was created, the team competed in the local Championship of Plovdiv. In the early years of Bulgarian football, there was no national league. The local championships, held at a regional level, were the most prestigious football tournaments in the country. Sportclub participated in the second division until 1933, when the team finished first and was promoted to Plovdiv's top tier as of 1939. In 1940, Sportclub became the Champion of Plovdiv for the first time.

In 1939 the team joined the National Football Division – the countrywide football league which had been formed only a year earlier and which included Bulgaria's top ten teams. However, in 1940 the league was disbanded because of World War II. By that time the club had officially changed its name to Plovdivski Sportclub (Sportclub of Plovdiv), primarily because several other teams in the league also had Sportclub in their names.

During World War II, the team participated in several other tournaments including the Tsar's Cup, which was considered Bulgaria's most prestigious knock-out cup tournament at the time and a predecessor of the current domestic cup tournament. In the Tsar's Cup the team reached the finals twice – in 1940 and 1942.

By the time of communist rule in Bulgaria in 1944, Sportclub had become one of the best performing teams in the country, reaching the finals in many tournaments. The club had become the biggest in the Plovdiv region in terms of members and continually set attendance records for the period.

The Club of the Railway Workers in Plovdiv

In the mid-1930s, the railway workers' and sailors' labour union established numerous cultural and sporting organisations across the country. The railway workers established a sports club in Plovdiv as well, since the city is one of the major railway centres in the country. On 13 June 1935 the club ZSK Plovdiv was founded, abbreviated from Zheleznicharski Sporten Klub Plovdiv (The sporting club of the railway workers in Plovdiv).

For the first few years, ZSK Plovdiv lagged behind other teams in the city such as Sportclub and Botev Plovdiv. The team was not recognized as a full member of the national sport federation until three years after its creation. However, by the early 1940s they had improved and in 1944 they won the Championship of Plovdiv.

From an economic perspective, the railway club contributed heavily to the development of sports in the region, making large investments in the improvement of sporting facilities and conditions in the city. Most notably, the powerful national railway company, through ZSK Plovdiv, was the main benefactor for the creation of a state-of-the-art multi-purpose stadium that opened in 1943. The stadium was constructed on the football pitch of the existing team Levski Plovdiv and as such was the home ground for both ZSK Plovdiv and Levski Plovdiv. As a result, the stadium was named ZSK-Levski.

Changes in Sportclub

In the years after 1944, the newly established communist rule embarked on several campaigns for the "reorganisation of the sporting clubs in Bulgaria" to make them align with the Soviet political agenda and follow the "Soviet model" of sport clubs. This meant that every local region should have its own sports club, but in order to make central investments more efficient for a larger member-base, only a few clubs were permitted per area. That led to the forced merger of clubs within the same locality.

Starting in 1944 Sportclub was merged with numerous other teams in the same district of Plovdiv. Being from an area with a diverse ethnic and religious population, the club was first merged with several lower-division so-called Armenian teams, such as Shant and Erevan. Another merger followed in 1945 with the Catholic club Parchevich. After this wave of mergers, like many other clubs in the country, the club was renamed to an abbreviation of the biggest clubs – S.P.-45, meaning Sportclub Parchevich – 1945. However, due to the non-Slavic background of the words "sport" and "club", the team was officially renamed again before the start of the season to Slavia Plovdiv.

In 1947 a new wave of consolidations saw Slavia Plovdiv merged with the cooperative workers' union team, Petar Chengelov. This merger created a club known as Slavia-Chengelov.