When the first fortified structures were built on the church hill in the 7th century, a court chapel was probably part of it.
Around 1200, an independent church was built on the Altenhof, which was part of the fortified royal court as an economic courtyard.
In the middle of the 13th century, the four-storey tower with a western entrance portal, which still exists today, was added to the west.
At the end of the 15th century, the small parish church was extended to the north with a Gothic choir and a chapel extension. St. Peter's Church was temporarily the burial place of the von Broich family.
In 1555, the Mülheim parish converted to the Protestant faith.
In the years 1870 - 1872, the nave of St. Peter's Church was renovated in neo-Gothic style, the Romanesque west tower and the late Gothic choir were preserved.
In 1912/1913, the entire church was extensively renovated, redesigned and painted. In 1943, St. Peter's Church was hit so badly by bombs that only the casing, some pillars and the stump of the tower remained.