Alexanderplatz (popularly known as "Alex") was the very center of East Berlin life and now is second only to the area where Kurfürstendamm and Budapester Strasse meet as the urban center of the reunited city. It received its name in 1805 in honor of Tsar Alexander I of Russia.
A hospice and chapel dedicated to St George were built here, outside the Oderberger Tor (one of the town gates), at the end of the 13th C., and the gate was thereafter known as the Georgentor (St. George's Gate). About 1700 a cattle market was established in this area, to be joined in the second half of the 18th C. by a wool market.
In 1701 the Elector of Brandenburg, newly crowned King of Prussia, entered the town through St George's Gate, which was then renamed the King's Gate (Königstor) in his honor. In 1777 Frederick II constructed an imposing bridge here, with colonnades (built 1777-80) designed by Karl von Gontard.
These can now be seen in the Kleistpark in front of the former Control Council Buildings.
The development of the square can be followed in eight porcelain panels in the pedestrian tunnel at the Hotel Stadt Berlin. They show (from left to right) the King's Gate in 1730, the cattle market on the counterscarp outside the King's Gate in 1780, the King's Bridge in 1785, the wool market in the Alexanderplatz in 1830, the Alexanderplatz about 1900, the square in 1930, the square in May 1945, as destroyed during the war, and the rebuilt square in autumn 1968.
Of the pre-war buildings in the square - the best-known of which included the massive Berolina statue (1895) by Emil Hundrieser and the Berlin Police Headquarters - only Berolina House (now the town hall of the central district of Berlin) and Alexander House on the south side survive. Apart from these, modern buildings now dominate this empty and dreary square. The S-Bahn and U-Bahn stations, which suffered heavy destruction in 1945, were modernized after the war. On the north side of the square stands the Hotel Stadt Berlin, built between 1967 and 1970, with 30 floors and rising to a height of some 120 m/394ft. Other large buildings in the Alexanderplatz are the Teacher's House (Haus des Lehrers), of 13 floors and built in 1964 (being the first new building erected in the square after 1945), the flat-domed Congress Hall and the 18-story travel agency building known as the Haus des Reisens. In 1969 Walter Womacka constructed the Fountain of Friendship between Peoples (Brunnen der Völkerfreundschaft). In the same year Erich John built the World Clock here.
A popular rendezvous point in Alexanderplatz is the Urania World Clock (Urania-Weltzeituhr). It occupies the site of an earlier monument, the figure of "Berolina" by Emil Hundriesser.