Today's town of Brand-Erbisdorf developed from two settlement germ cells, the older Waldhufendorf Erbisdorf, founded around 1150, and Brand, which emerged as a mining settlement around 1515 in the course of the general boom in mining in the Ore Mountains. Numerous smaller pits initially formed the Brander Revier, which developed here, but between 1557 and 1570 the depths in the pits increased, which made more effective dewatering with artificial tools necessary. In the middle of the 15th century, the first water release tunnel for the Brander Revier, the Brandstollen, was driven to drain the impact water used to drive the art tools and the lifted mine water. In the 16th century, this heritage adit was then replaced by the Thelersberger adit, which was about 25 meters deeper. In 1526, an older tunnel was re-opened for this and advanced in the direction of Brand and Erbisdorf. The Thelersberger tunnel drained a large number of pits, especially in the Himmelsfürst district between Erbisdorf and Langenau, and developed into the most extensive and important drainage tunnel in the Brand district. The tunnel, including its many tunnel wings, was about 55 kilometers long around 1800, although its main section only stretched over seven kilometers. In a northerly direction it extends as far as the Obergöpelschacht in Zug and as far as the Hospitalwald, in an easterly direction almost as far as Berthelsdorf and in a southerly direction under the Freiwald and under the Oberlangenau stamp mill ponds. The Saxon Elector August I also drove through the tunnel. A sandstone plaque that was installed in the Thelersberger Stolln to commemorate this event on March 3, 1556 is now in the Freiberg City and Mining Museum. As a sovereign tunnel, it was also directly subordinate to the Freiberg Mining Administration and the later Revierwasserlaufanstalt for a long time. Due to the deeper water release tunnels driven from Freiberg, the Thelersberg tunnel lost its outstanding importance in the 19th century, but was maintained by the Revierwasserlaufsanstalt until the local silver mines were stopped. The last general tunnel inspection took place in 1850.