In the middle of 13th century, Count Konrad of Freiburg left the old Martin Chapel in middle of the city and four neighbouring farms to the Franciscans. The construction of the monastery complex took place after 1262 until about 1350. Over time, the decoration of the church was adapted to the then prevailing style; the most far-reaching one was the baroque introduced after 1713/14 and neo-Gothic style of the interior after 1875, when Saint Martin had served as a parish church for almost 100 years.After demolition of monastery buildings in the west and south, the current Town Hall square was created in 1845, where the monument to Karl von Rotteck (today before KG II) was erected in 1848, and where Alois Knittel Fountain monument to the monk Berthold Schwarz, who is said to have invented the powder, was erected in 1853, according to the local tradition in the Franciscan monastery around 1400.