There are various theories about the origin of the unusual name Titisee:
In the Alemannic dialectTeti means "little child" or "baby". Tetisee or Titisee would then be a lake from which, according to local legend, small children came, similar to the story told in other places that babies are delivered by a white stork. Stories about babies coming from lakes were widespread in Central Europe. Consistent with this theory, is the fact that the Titisee is a very high altitude lake and that, also according to legend, it is bottomless. Such lakes were formerly attributed with special numinous powers.
According to another theory, the Roman general, Titus, was supposed to have camped in the area of the Titisee. The lake was said to have impressed him so much that he gave his name to it. This is also the reason why, today, a crude replica of a Roman galley plies the Titisee.
According to a legend a nobleman called Titini hunted in the area around the lake in the 12th century.
Also the arum lily, formerly known in the region as the Tittele, could be the origin of the name, even though it no longer occurs by the Titisee.
History
In 1840, two sarcophagi made of worked tuff were found below a knoll by the outflow of the Gutach from the Titisee. In 2011, the archaeologist, Andreas Haasis-Berner, published an article stating that they had to date to the period between 700 and 900. Hitherto, it had been thought that the High Black Forest had been unsettled during the first millennium. The first records of the lake date to 1050 and the abbey of Allerheiligen in Schaffhausen, where the name Titinsee is mentioned. The name Dettesee is also mentioned in a deed from the parish of Saig that dates to 1111. The name of the lake adopted its present from around 1750.
Winter freezing
The Titisee takes a long time to freeze over in the winter owing to the winds, which keep the surface of the water moving almost all continuously. For the frozen lake to be opened for use, it must have a solid ice thickness of at least . When conditions appear favourable for the opening the lake, daily ice measurements are taken by the Titisee-Neustadt municipal authorities at three or four places. If opening the ice to public use is possible, and those responsible give it their blessing, specific, demarcated areas of the lake are opened, but never the whole lake. These regulations were put in place after an accident in 1966. Up to that time, the lake had been used in winter as a landing strip for small aircraft. On 14 January 1966, a tractor with a snowplough was clearing the landing strip of snow when it broke through the ice and sank to the bottom of the lake, taking the driver, Walter Wilde, with it. His body was only recovered 2 weeks later.