text: In 1931, AS-23 won their first Bulgarian championship and The Tsar's Cup, followed by another Tsar's Cup in 1941. The club's stadium (completed in 1938) was named Athletic Park and was situated where the Bulgarian Army Stadium now resides.
  On 9 November 1944, with the support of Mihail Mihaylov, an accountant at the Ministry of War and a patron of Shipka Sofia, a unifying agreement was signed, merging AS-23, Shipka, and Spartak (Poduene) to form Chavdar Sofia. Gen. Vladimir Stoychev from AS-23, who at the time was fighting on the front in World War II, was appointed (by telegram) as the new club's chairman. Lawyer Ivan Bashev, a future Bulgarian foreign minister, was appointed club secretary and the person in charge of football.
  1948–1962
  With the help of Mihail Mihaylov again, in February 1948, Chavdar became the departmental club of the Central House of the Troops ("Centralnia Dom na Voiskata") and took on the name of CDV. Looking for ways to stop the club's decline, CDV's administrators sought to merge it with another club. In May 1948, an agreement was reached between CDV and Septemvri Sofia (which had already earned a place in the play-offs) for uniting the clubs under the name "Septemvri pri CDV" (Septemvri at CDV). The contract was signed on 5 May 1948, which is officially considered the club's date of foundation.