sentences:  The only known architects during the church's construction are Hans Marx, who worked on the church until 1426, as well as Jorg, who was responsible until 1439.Both men probably supervised work on the nave.Under the reign of Prince-elector Frederick I a noted specialist in the construction of church towers, Niclaus Eseler, came from Mainz to Heidelberg and was probably responsible for the execution of the primary work on the spire of the Church of the Holy Spirit.