The area has been inhabited since mesolithic times. The flint tools found here from that era (6,000 - 4,500 B.C.) are clearly defined and known as the Oldesloer Stufe. For a number of years in the 18th Century the Moravian Church had a Congregation in Bad Oldesloe. It was called "Pilgerruh", i.e. "Pilgrims' Rest". It was given up because of difficulties with the Danish Church authorities. At that time the Duchy of Holstein was ruled by the King of Denmark within the Holy Roman Empire. The famed nineteenth-century classicist and legal scholar Theodor Mommsen was born in Bad Oldesloe in 1817.