According to this, there are a large number of different names, but they all go back to the same phoneme stem. Their respective use in the sources appears arbitrary and random.
In the course of time the name changed many times: trut munia 899, Thortmanni, Trutmania, Trotmunni 939, Tremonia 1152. From the 13th century on, the Dortmunde appeared for the first time, but it was not until a few centuries later that it became generally accepted.
In the Middle Ages 1389, when the city had withstood the siege of 1200 knights under the leadership of the Archbishop of Cologne, it chose as its motto a saying that is still upheld today by traditional societies: So fast as Düörpm.
In the past, the city was called Dortmond in Dutch, Tremonia in Spanish and Trémoigne in Old French. However, these exonyms have fallen into disuse and the city is now internationally known by its German name of Dortmund. The common abbreviation for the name of the city is “DTM”, the IATA code for Dortmund Airport.
