Siegfried I (died 16 February 1084) was the Abbot of Fulda from 25 December 1058 until he became Archbishop of Mainz in 6 January 1060.
Siegfried was a member of the Frankish Reginbodonen family of the Rhineland. His family furnished counts in the Königssondergau and burgraves and vogts of Mainz. Siegfried was educated in the monastery of Fulda and became a monk there. On 25 December 1058, he was appointed abbot and 6 January 1060, the Empress Agnes appointed him Archbishop of Mainz. In Spring 1062, he entered the political realm as a prominent member of the faction surrounding Anno II of Cologne. Nevertheless, he never had the political influence of Anno or Adalbert of Bremen, called dritt Kraft. Siegfried himself sided first with the emperor in the Investiture Controversy.
In Winter 1064 – 1065, he undertook a pilgrimage to Jerusalem. In 1070, he took a pilgrimage to Rome to seek the permission of Pope Alexander II to lay down his title and abdicate, but the pope refused him. Together with Anno II of Cologne, in 1071, he founded a Benedictine monastery at Saalfeld.
In 1072, under the pretext of a pilgrimage to Santiago de Compostela, he sojourned at Cluny, where he met the Abbot Hugh the Great. The Mainzers, however, demanded his return before he made it to Spain. Upon his return, he ardenly undertook the Cluniac reform in his diocese. In 1074, in that vein, he established the monasteries of Ravengiersburg and Hasungen.
When, in 1076, during the Investiture Controversy between the Holy Roman Emperor and the Roman Catholic Pope, Pope Gregory VII excommunicated Emperor-elect Henry IV, Siegfried did an about-face and, at a general assembly of German Aristocrats in Tribur in October 1076, participated in the election of an anti-king, supporting the nobility opposing the Emperor in the civil war that became known as the Great Saxon revolt. Subsequently, Siegfried was driven from his diocese by the outraged royalist citizenry revolting against his rule. Nonetheless, on 25 March 1077, he crowned the Emperor's brother-in-law, duke Rudolf of Rheinfelden as Antiking, since the allied rebels of which he was a part needed the military prestige and might of a king to offset the power of the established monarch given his rapprochement with the Pope. On 26 December 1081, he crowned Herman of Salm as the second anti-king in Goslar. After 1081, he ceased to involve himself in public affairs until his death at Hasungen, where he was buried.
| Catholic Church titles | ||
|---|---|---|
| Preceded by Luitpold |
Archbishop of Mainz 1060–1084 |
Succeeded by Wezilo |