At the end of the 12th century, the city emerged from the two merchant settlements Berlin and Cölln, located on both sides of the Spree river in what is now the Mitte borough. In 2008, state archaeologists found an oak beam that probably dates back to 1183, making Berlin 54 years older than was previously assumed. The excavations took place at Petriplatz, one of the oldest places in the city.
Berlin dates its official founding to 1237, the year of the first recorded mention of Cölln. The first documentary reference to Berlin followed in 1244.
Berlin is given a new town seal depicting, for the first time, two bears.
The church Nikolaikirche (St. Nicholas’s) is built in the area known today as the Nikolaiviertel. The first documentary reference of the Marienkirche (St. Mary’s) dates from 1292.
Berlin and Cölln form a union in order to protect and expand their rights against the margrave. Twelve aldermen from Berlin and six from Cölln hold their meetings in the new town hall they share. Each town has its own administration and budget, maintaining internal independence while presenting a united front to the outside world.
The Mark Brandenburg becomes an Electorate.
Berlin-Cölln becomes a member of the Hanseatic League, representing the cities of its region at the League’s meetings in Lübeck. This association of merchants and cities permits the development of wide-ranging trade relations, but Berlin-Cölln carries no great weight in the League. The city gives up its membership in 1518.
A Berlin town hall on the site of the northwest corner of today’s Berlin Town Hall in the Mitte borough is mentioned for the first time.
Berlin and Cölln have roughly 8,500 inhabitants and 1,100 buildings. Between them, the twin cities have three town halls, three hospitals, churches, and monasteries with residences for the clergy and the court of the margrave.