Kingdom of Serbia became part of the new state, Kingdom of the Serbs, Croats and Slovenes. which was formed on 1 December 1918. Even though the industry was on a very low level of development, the state was among the first 10 countries in the world which developed their own aircraft production. Originally, only the parts produced in foreign factories were assembled, but very soon the production of domestic components began, so as the engineering. The forerunner of the domestic aircraft industry was the Airplane workshop (Aeroplanska radionica), which was established in 1920, at the airfield in Novi Sad. The assembling of the trial series of Hansa-Brandenburg C.I. The series was named SBr, as this type of plane was known in Serbia as srednji Brandenburg ("middle Brandenburg").