Otto of Nordheim (c. 1020 – 11 January 1083) wasDuke of Bavaria from 1061 until 1070. He was one of the leaders of theSaxon revolt of 1073–1075 and theSaxon revolt of 1077–1088 against KingHenry IV of Germany.

Otto was born about 1020, the son of Count Bernard ofNordheim (d. about 1040) and his wife Eilika.^[1] The rich and influentialSaxon comital dynasty of Nordheim was first mentioned about 950, its descendance has not been conclusively established: there is possibly a relationship with theImmedinger family of legendary DukeWidukind, while according to theMagdeburg archbishopEric of Brandenburg, Otto's grandfather Siegfried I of Nordheim was a son of CountSiegfried of Luxembourg.

The Nordheim counts held large Saxon estates on the upperLeine andWerra rivers as well as on theWeser and itsDiemel andNethe tributaries and on the lowerElbe river. They also acted asVogts (reeves) of theCorvey,Gandersheim,Helmarshausen,Bursfelde, andAmelungsborn. Otto succeeded his father as count of Northeim about 1049, then one of the most influential Saxon nobles along with theBillung dukeBernard II and the Udonid counts ofStade.

After the death of theSalian emperorHenry III in 1056, his widow, Dowager EmpressAgnes, appointed Otto duke ofBavaria in 1061^[2] in order to gain his support as the mother of, and regent for, the young king Henry IV. The following year (1062), however, when Agnes handed power to her confidant BishopHenry II of Augsburg, Duke Otto was among thoseprinces who assisted ArchbishopAnno II of Cologne in seizing control of Henry IV and the regency, in the so-calledCoup of Kaiserswerth.^[3]

Otto took a prominent part in the government of the kingdom during Henry's minority. He led asuccessful expedition intoHungary in 1063 to reinstall KingSolomon (betrothed to Henry's sister,Judith of Swabia), who had been driven out by his uncleBéla I. The next year Otto went toItaly to settle a papalschism caused by the appointment ofAntipope Honorius II. Otto was also instrumental in securing the banishment from court of the overly powerful ArchbishopAdalbert of Hamburg-Bremen. He crossed theAlps in the royal interests on two other occasions and in 1069 shared in two expeditions into the lands of thePolabian Slavs (Wends) east of Germany.^[3]

So far, Otto was on good terms with the young king. However, he neglected his Bavarian duchy and instead added to his Saxonallodial possessions in the southernHarz range, which ultimately led into conflict with Henry IV, who aimed at the consolidation of his royaldomains in this region.^[3] In 1070 dubious accusations were brought against him by oneEgeno I of Konradsburg of being privy to a plot to murder the king, and it was decided Otto should submit totrial by combat with his accuser atGoslar.

Fearing for his safety, Otto asked for a safe-conduct to and from the place of meeting. When this was refused he declined to appear and was consequently placed under theimperial ban and deprived of Bavaria, while his Saxon estates were plundered.^[4] He obtained no support in Bavaria, but raised an army among the Saxons and carried out a campaign of plunder against Henry until at Pentecost 1071, when he submitted. In the following year he was released from custody and received back his private estates,^[3] though not the Bavarian ducal title, which had been granted to his former son-in-lawWelf I, the divorced husband of Otto's daughterEthelinde.^[5]

According toBruno, author ofDe bello Saxonico (On the Saxon War), when the Saxon rebellion broke out in summer 1073, Otto delivered an inspiring speech to the assembled nobles atWormsleben, after which he took command of the insurgents. By thePeace of Gerstungen on 2 February 1074, the Duchy of Bavaria was formally restored to him,^[3] which however met strong opposition by the local nobility, with the result that Otto's former son-in-law Welf I remainedde facto Duke of Bavaria.^{[citation needed]} He also participated in the second rising of 1075^[3] following the demolition ofHarzburg Castle.^{[citation needed]} Defeated in theBattle of Langensalza on June 9, he surrendered and was again pardoned by King Henry who made him administrator of the Saxon duchy.^[3]

When theInvestiture Controversy between Henry IV andPope Gregory VII culminated in theexcommunication of the king in 1076, Otto attempted to mediate between Henry and the Saxon nobles convened atTrebur,^[3] but when these efforts failed he again joined the insurgents. Otto was not the leader of the Saxon revolt, however. Once he was assured that the duchy of Bavaria would be returned to him, Otto accepted the election ofRudolf of Rheinfelden asantiking ofGermany. Through his skill and bravery, Otto still inflicted defeats on Henry's forces at the battles ofMellrichstadt,Flarchheim andHohenmölsen.^[3]

Otto remained in arms against the king until his death on 11 January 1083.^[3] He is buried in the Nicolai Chapel inNortheim.^[6] His personal estates in Saxony later passed toLothair of Supplinburg, who about 1100 married Otto's granddaughterRichenza of Northeim. After Richenza,German queen from 1125 andHoly Roman Empress from 1133, died in 1141, the allodial lands were inherited by her daughterGertrude and her husband, theWelf dukeHenry the Proud.

Otto is described as a noble, prudent and warlike man, and he possessed great abilities. His repeated pardons showed that Henry could not afford to neglect such a powerful personality, and his military talents were repeatedly displayed.

About 1055 Otto marriedRichenza, formerly reckoned as a daughter of DukeOtto II of Swabia, but probably a descendant of theBillung dynasty. The couple had four sons and three daughters.^[3]

• Henry the Fat (1055–1101), Margrave ofFrisia (1055–1101)^{[citation needed]}
• Otto II, Count of Nordheim^{[citation needed]}
• Siegfried III (1050–1107), Count of Boyneburg^{[citation needed]}
• Kuno (1050/60–1103), Count ofBeichlingen^{[citation needed]}
• Ida, married CountThimo of Wettin, mother of MargraveConrad of Meissen^{[citation needed]}
• Ethelinde (born 1050/60, date of death unknown), married DukeWelf I of Bavaria in 1062, divorced 1070; secondly married Herman I,Count of Calvelage in 1070^[7]
• Matilda, married Count Konrad II of Werl-Arnsberg^{[citation needed]}

• H. von Hindte, 'Otto von Northeim,'Lexikon des Mittelalters, vol. 6 (1993), col. 1578.
• M. Black-Veldtrupp,Kaiserin Agnes (1043-1077) Quellenkritische Studien.
• Lampert of Hersfeld,Annales, in O. Holder-Egger, ed.,Lamperti monachi Hersfeldensis Opera, MGH SS rer Germ 38 (Hanover, 1894), pp. 1–304, accessible online at:Monumenta Germaniae Historica (in Latin)
• Annales Altahenses maiores (written c.1075), ed. W. Giesebrecht and E. L. B. von Oefele, MGH SS rer Germ 4 (Hannover, 1890, 2nd edition), accessible online at:Monumenta Germaniae Historica (in Latin).
• Giesebrecht, Wilhelm von (1881–1890),Geschichte der deutschen Kaiserzeit, vol. III, Leipzig{{citation}}: CS1 maint: location missing publisher (link)
• Mehmel, H. (1870),Otto von Nordheim, Herzog von Bayern, Göttingen{{citation}}: CS1 maint: location missing publisher (link)
• Neumann, E. (1871),Duc Ottone de Nordheim, Breslau{{citation}}: CS1 maint: location missing publisher (link)
• Riezler, S. (1878),Geschichte Bayerns, Gotha{{citation}}: CS1 maint: location missing publisher (link)
• Vogeler, A. (1880),Otto von Nordheim, Göttingen{{citation}}: CS1 maint: location missing publisher (link)
•  This article incorporates text from a publication now in thepublic domain: Chisholm, Hugh, ed. (1911). "Otto of Nordheim".Encyclopædia Britannica. Vol. 20 (11th ed.). Cambridge University Press. p. 376.

• Otto von Northeim (in German)

• 1020s births
• 1083 deaths
• 11th-century dukes of Bavaria

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