Odo I, Margrave of the Saxon Ostmark

Odo (or Hodo) I (also Huodo or Huoto) (c. 930 – 13 March 993) was margrave in the Saxon Eastern March of the Holy Roman Empire from 965 until his death.

Odo was, if the onomastics are correct, a son (or maybe a nephew) of Christian (d. 950), a Saxon count in the Nordthüringgau and Schwabengau of Eastphalia. Count Christian, probably a scion of the Billung dynasty, had married Hidda (d. 970), a sister of Gero, margrave of the vast marca Geronis in the lands settled by Polabian Slavs. From 945 he also ruled over the adjacent gau of Serimunt beyond the Saale river.

In 965, Margrave Gero died and his great marca Geronis was divided into five smaller marches. Count Thietmar, a known son of Hidda, and Odo inherited large parts of his march: Odo received the so-called marca Orientalis or Eastern March, stretching from the Gau Serimunt in the west up to the remotest outposts on the Bóbr river in the east, while Thietmar appeared as margrave of southern Meissen after 970. Both are buried at Nienburg Abbey, a foundation of Thietmar and his brother Archbishop Gero of Cologne, which too provides evidence of their probable relationship.

Odo spent the first years of his rule to subdue the Slavic tribes settling in the eastern parts of the Saxon Ostmark. He held comital rights in the gau of Nizizi, comprising the lands between the Mulde, Elbe and Black Elster rivers, and appeared with the title marchio (margrave) only in 974, though he had held further marcher territories (officially as a county) since 965. In that same year (974), Odo was made Count in the Saxon Nordthüringgau, still rivalling with Margrave Thietmar.

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