After the
Duchy of Saxony had been conquered by the
Frankish Kingdom, Emperor
Charlemagne in 800 founded a missionary diocese at his
eastphalian court in
Elze (
Aula Caesaris), about west of Hildesheim. His son King
Louis the Pious established the bishopric at Hildesheim in 815, dedicated to
Virgin Mary. According to legend delivered by the
Brothers Grimm, the king was hunting in the wintery woods of Elze, when he realized that he had lost his pendant with the
relic of Blessed Virgin Mary. Distraught he sent out his attendants who finally discovered a flowering rose bush with the relic in his branches, which it would not let go. Louis had a chapel built by the side of the rose, the later
St. Mary's Cathedral. A
rosa canina is still growing at the
apse of the cathedral, called the
Thousand-year Rose (
Tausendjähriger Rosenstock). His son King
Louis the German appointed the former
archbishop of Rheims,
Ebbo, as bishop between 845 and 847. Ebbo's successor
Altfrid began the construction of
the cathedral. A close adviser to Louis the German, Altfrid founded
Essen Abbey. During the reign of the Saxon
Ottonian dynasty Hildesheim, together with the neighbouring bishoprics of
Halberstadt and
Magdeburg, became the central ecclesiastical territory of the
Holy Roman Empire. Bishop
Bernward (993-1022) built up the cathedral district with a strong twelve-towered wall, built the
Michaeliskirche, and commissioned
bronze doors for the cathedral. During the tenure of his successor
Gotthard (1022-1038), the cathedral school became a center for learning. Bernward and Gotthard added much to the architectonic and cultural tradition of the present-day
World Heritage Site. At the
Reichstag at
Mainz of August 15, 1235 Bishop
Conrad II reached the official acknowledgement of Hildesheim as a
Prince-bishopric (
Hochstift) by Emperor
Frederick II. As a negative consequence of this success, Hildesheim began to interfere with the neighbouring
Welf duchy of
Brunswick-Lüneburg, culminating in the
Hildesheim Diocesan Feud 1519-1523 with the warlike Brunswick duke
Henry the Younger that led to a significant loss of territories. In the 16th century, most of the diocese as well as most of the state of Hildesheim switched to
Protestantism. But the Bishopric managed not only to retain its independence from the surrounding Protestant states of
Brunswick-Lüneburg, but also to retrieve large parts of the lost estates, mostly because its bishops were members of the powerful
House of Wittelsbach from 1573 until 1761, the last
Clemens August of Bavaria from 1723, who also was archbishop and
prince-elector of
Cologne, prince-bishop of
Münster,
Osnabrück and
Paderborn as well as
Grand Master of the
Teutonic Order. Hildesheimer Dom 2015.JPG|
Hildesheim Cathedral Hildesheim, ehemalige fürstbischöfliche Residenz - Bischöfliches Generalvikariat.jpg|Former palace of the prince-bishops, today general vicariate of the diocese Hildesheim-Marienburg hell.jpg|
Marienburg Castle (Hildesheim) Hildesheim-Burg.Steuerwald.Torturm.03.jpg|
Steuerwald Castle In the course of the
German Mediatisation of 1803, Hildesheim was secularised and its territory was annexed to
Prussia. Four years later, however, Prussia lost it to the newly established
Kingdom of Westphalia. The
Congress of Vienna of 1815 gave the territory of the former prince-bishopric to the
Kingdom of Hanover. , 1645 ==Subdivisions
(Ämter)==