Important men came out of this family. The most famous personality was Saint Brun of Querfurt, who was born in the castle in 973/974 and beheaded in 1009 by a pagan prince of the Pruzes. He is still remembered by memorial plaques at the castle church and the town hall. The Braunsstrasse, the Braunsmühle, the Braunsberg, the Eselsmühle, the Wiesenhaus and the Braunsbrunnen can also be associated with the Querfurt town saint. The legend of the Nine is connected with the Braunsbrunnen. Brun is said to have miraculously caused a spring to gush. This water source was to be of great importance for the later centuries. In 1900, a stately iron pump was erected on this spot. Later the present well was built.

The Braunsbrunnen, named after Brun, was the richest in water in the village. The inhabitants carried the water home with butts. In order to keep the well clean, it was cleaned on the Wednesday after Whitsun. All inhabitants of Thaldorf had to participate in this cleaning. Old people, who could not fulfill this duty anymore, redeemed themselves by paying a small sum of money. In the course of the centuries this necessary custom developed into a folk festival. The fountain was decorated with birch greenery and garlands. The collected ransom was given as a reward to the men in the form of liquor and to the women in the form of cakes. According to an old traditional custom, afterwards people splashed each other with plenty of water. The symbol of "purification" was supposed to protect people from diseases or misfortunes and keep them young. In 1891, the open brown well was covered for reasons of cleanliness and equipped with a wooden pump. The work was carried out by the inhabitant Gottlieb Straubel. Around 1900 the wooden pump was replaced by the iron pump that is still there now. The time of fetching water with butts came to an end in 1927. At that time, in the city of Querfurt, the water pipeline was put into operation. However, the Braunsbrunnen remained as a traditional well.

The Querfurt master builder Paul Jacob and his journeymen masoned a new fountain enclosure in 1935. Two years later, the sculptor Otto from Querfurt created the corresponding fountain monument for the fountain. It shows St. Brun surrounded by a child, which refers to the legend of the nine-legged people, and a donkey, on which Brun is said to have ridden and which is connected with the legend of the "Steady Donkey" or the "Donkey Meadow". From the tradition of cleaning the wells, the well festival developed every year, which has been brought back to life today, and on the occasion of which a lord of the well is elected. Since 1989 it has been organized by the Thaldorf Whitsun Boys and always takes place on the Wednesday after Whitsun (Garlic Wednesday) at the Brown Fountain.