815: Emperor Louis the Pious founds the diocese of Hildesheim – in contrast with his original plans of founding it in Elze - and has a small church erected on the cathedral hill.
Around 820: Gunthar, the first bishop of Hildesheim, erects a cathedral church to the south of the imperial chapel for the canonical hour as part of the divine office of the cathedral chapter.
852 to 872: After three days of prayer and fasting, Bishop Altfrid orders the construction of a new cathedral to be erected on top of the imperial chapel and along its western extension.
Around 963: South of the cathedral, Bishop Othwin erects a chapel to honour Saint Epiphanius of Pavia (438–496). In 963, Othwin brings St. Epiphanius’ remains to Hildesheim.
Arounf 1015: Bishop Bernward decorates the cathedral with works of art. For the bronze ‘Bernward-doors’ he commissioned the reconstruction of the western crypt as well as erecting a new main west portal.
Around 1035: Bishop Gotthard orders the demolition of the western end of the cathedral and builds a new westwork consisting of an atrium and a bell tower. Above the former Epiphanius Chapel a college of canons is formed along with a church.
1046: A large fire in Hildesheim causes major destruction to the cathedral.
1044 to 1054: Bishop Azelin commences a new development to the west of the cathedral with the purpose of shifting the cathedral to the west as a whole.
1061: Bishop Hezilo consecrates a new cathedral on the foundation walls of the earlier Altfrid Cathedral. The Cathedral started by Azelin further to the west is given up due to massive construction defects. Bishop Hezilo fits out his Episcopal palace (today’s Episcopal General Vicariate) in the western transept.
1079: Building of the Laurentius Chapel under Bishop Hezilo (today’s sacristy of the cathedral)
1321: Bishop Otto von Wohldenberg builds the chapel of St. Anne in the middle of the cloister. It is presumably during this period that the seeds of the ‘millennium rose bush’ took hold by the choir apse.
From 1330: Building of the gothic aisle chapel
1440: Extension of the Laurentius chapel to the south by one aisle.
Around 1444: Redevelopment of the Antonius Chapel in the building line of the widened Laurentius Chapel.
1718 to 1770: baroque interior decoration of the cathedral with stucco and painting
1841 bis 1850: Demolition of the ‘Gotthard-westwork’ and the side chapels and construction of a double tower façade following the example of St. Gotthard in Hildesheim
March 22nd 1945: Bombardment leading to the cathedral burning out completely. The north side, the transept and the east choir collapse. The roofs and west towers burn out. After the end of the war further wall fragments collapse.
1950: Design competition for the rebuilding of the cathedral. The architect W. Fricke from Hanover wins first prize. Staying as true to the original as possible he plans to erect the cathedral on the foundation walls of the Hezilo Cathedral.
March 27th 1960: Consecration of the new cathedral by Bishop Heinrich Maria Janssen
Origin: Höhl, Brandt, Kruse, Scharf-Wrede: Welterbe. Der Hildesheimer Dom und seine Schätze; Bernward Mediengesellschaft, Hildesheim 2007