On 14 August 1370, Charles IV, Holy Roman Emperor gave city privileges to the place that subsequently was named after him, according to legend after he had acclaimed the healing power of the hot springs. However, earlier settlements could be found in the outskirts of today's city.
Due to publications by doctors like David Becher and Josef von Löschner, the city developed into a famous spa resort and was visited by many members of European aristocracy. It became popular after the railway lines to Eger (Cheb) and Prague were completed in 1870.
The number of visitors rose from 134 families in the 1756 season to 26,000 guests annually at the end of the 19th century. By 1911 that figure had reached already 71,000 but World War I put an end to tourism and also led to the collapse of the Austro-Hungarian Empire by late 1918.
Despite the right to self determination declared in Woodrow Wilson's Fourteen Points, the large German-speaking population of Bohemia was incorporated into the new state of Czechoslovakia against their will in accordance with the Treaty of Saint Germain. As a result, the German-speaking majority of Carlsbad protested. A demonstration on 4 March 1919 passed peacefully, but later that month six demonstrators were killed by Czech troops after a demonstrations turned unruly.
In 1938, the Sudetenland, including Carlsbad, became part of Nazi Germany according to the terms of the Munich Agreement. After World War II, in accordance with the Potsdam Agreement, the vast majority of the people of Carlsbad were forcibly expelled from the city because of their German ethnicity. In accordance with the Beneš decrees, their property was confiscated without compensation.source: Wikipedia.org