Ulrich von Ensingen ' the master builder of the great cathedral of Ulm ' began construction of the octagon of the north tower in 1399.
Ulrich von Ensingen built part of the cathedral, but he didn't build the octagon of the north tower.
mnli hypothesis: Ulrich von Ensingen built part of the cathedral, but he didn't build the octagon of the north tower. premise: Ulrich von Ensingen ' the master builder of the great cathedral of Ulm ' began construction of the octagon of the north tower in 1399.