RFG), the predecessor of the current Bulgarian top division league. Through the mergers, the club originally named Sportclub kept its original colours and core team, with only a small number of players considered good enough to find a place in the first team of the "new" club. The supporters remained loyal to the colours and the players, and the followers of the assimilated clubs joined them, increasing the number of fans and members of the largest club in Plovdiv at that time. Though technically the numerous clubs merged, because of the sheer size of Sportclub in terms of members, the smaller clubs were effectively assimilated into the larger club. Changes in ZSK For ZSK Plovdiv, reorganisation began in the autumn of 1944. The club was initially merged with the team with which it shared a stadium, Levski Plovdiv, to form ZSK-Levski. However, unlike most other forced mergers at that time, the ZSK-Levski merger was dissolved in less than a year. After the separation in 1945, ZSK was renamed to Lokomotiv Plovdiv similar to other teams in various Eastern bloc countries which were connected with the railways. Lokomotiv Plovdiv and Levski continued to co-exist as separate entities, still sharing the same stadium. Although railway workers' club was financially backed by the national railway, in the early years of communist rule the football team competed only at the third level of the recently formed national league. Furthermore, the club was the smallest in Plovdiv in terms of members and attracted only a modest number of spectators for its games, despite its large, state-of-the-art stadium. Merger of Slavia-Chengelov and Lokomotiv Plovdiv In the summer of 1949, the Bulgarian Communist Party adopted a new principle governing the construction of sports clubs. Clubs had to serve primarily as physical fitness departments of politically important national enterprises, such as oil refineries, police, army, national railway, and others. Thus, the geographical location of a club was no longer important and clubs were assigned to the major institutions in the country. The reorganisation of 1949 assigned Lokomotiv to assimilate Slavia-Chengelov, since Lokomotiv was already a team strongly associated with a significant national enterprise. By that time, Slavia-Chengelov was the largest club in Bulgaria in terms of members, and with an even larger fan base. DSO Energiya was formed from this merger prior to the start of the 1950 season. They used Slavia-Chengelov's colours (white, red, and black) for