The Berlin border crossings were border crossings created as a result of the post-World War II division of Germany. Prior to the construction of the Berlin Wall in 1961, travel between the Eastern and Western sectors of Berlin was completely uncontrolled, although restrictions were increasingly introduced by the Soviet and East German authorities at major crossings between the sectors. This free access, especially after the closure of the Inner German border, allowed the Eastern Bloc emigration and defection to occur. East German officials, humiliated by this mass defection, subsequently chose to erect the Berlin Wall in order to prevent residents from leaving East Germany.
After the construction of the Berlin Wall in 1961, border stations between East Berlin (regarded as East Germany's capital by the German Democratic Republic but unrecognized by the Western Allies) and the sectors controlled by those three Western Allies were created. Although there were few crossings at first, more sites were built over the wall's lifespan. Many East Germans crossed the wall illegally by climbing over it, sailing around it, or digging under it, while many others died while attempting to cross.
Border control procedures
Between West Berlin and German Democratic Republic (GDR) territory, the border stations were developed very effectively on the GDR side. (The official designation for controlled border traffic was Grenzübergangsstelle, GÜSt: border crossing site.) Border officials and customs agents would monitor incoming and outgoing traffic according to established procedures, at times with the utmost scrutiny. A strict division of labor among the various organizations was the rule. The security of the outward-facing border and of the border crossings was maintained by special security divisions of the GDR border guard troops (German abbreviation SiK, short for Sicherungskompanien).
The actual inspections of vehicle and pedestrian traffic were carried out by the passport control units (German abbreviation PKE, short for Passkontrolleinheiten). The PKE units were not under the command of the GDR border guard troops and thereby the Ministry of Defense, but the Ministry for State Security (Division VI / Department 6, Passport Control). While on duty at the border stations, however, the PKE would wear the same uniforms as the border guard troops. For personal inspections, highly qualified and specially trained forces were used exclusively. The passports, identification cards, etc., could be transmitted from the inspection sites to a processing center using closed-circuit television and ultraviolet light, where they were recorded. From there, commands were issued using a numeric display to the passport control unit, for example "flip page", "request additional documentation", "delay processing", ask predefined questions, etc.
On the West Berlin side, police and customs agents were stationed. No personal inspections usually took place there. At the transit crossings (sites for traffic passing into the GDR en route to another country), statistical demographic data about travelers would be recorded (travel destination, etc.), and travelers would occasionally be inspected, when appropriate, for the purpose of criminal investigations (police "dragnets"). Freight traffic bound for other countries was subject to customs processing. Shipping to the Federal Republic of Germany was only subject to statistical record-keeping and, under certain circumstances, sealing of the cargo. At Checkpoint Bravo (Dreilinden) and Checkpoint Charlie (Friedrichstraße), the Allied occupation forces had established checkpoints, but they were not relevant to regular personal and business traffic. They served as processing stations for military units as well as a display of military presence. Their designated authority to perform further inspections was utilized only in extremely rare cases. Signs directed travelers passing through the GDR to report any suspicious events that might have occurred during their transit; by these means, information was to be gathered regarding, for example, the arrest of West German citizens.