Gero the Great

Gero I (c. 900 – 20 May 965), called the Great (Latin magnus), ruled an initially modest march centred on Merseburg, which he expanded into a vast territory named after him: the marca Geronis. During the mid-10th century, he was the leader of the Saxon Drang nach Osten.

Gero was the son of Count Thietmar, tutor of Henry I. He was appointed by King Otto I to succeed his brother, Siegfried, as count and margrave in the district fronting the Wends on the lower Saale in 937. His appointment frustrated Thankmar, the king's half-brother and Siegfried's cousin, and together with Eberhard of Franconia and Wichmann the Elder, he revolted against the king (938). Thankmar was dead within a year and his accomplices came to terms with Otto. Gero was kept in his march.

During the insurrection of his opponents, Gero had been prosecuting a losing war against the Slavs in 937–938. The losses his troops sustained could not be made up for by the produce of the land nor by tribute, since the Slavs refused to pay. As an important marcher lord, Gero's command included milites ad manum Geronis presidis conscripti, that is, a "military following," "warband of vassals or companions," or "specially chosen group of fighters" differentiated from the rest of the army (exercitus). These men formed the elite of Gero's troops.

In 939, an Obodrite attack left a Saxon army routed and its margravial leader dead. Gero in revenge invited thirty Slav chieftains to a banquet whereat he killed all but one, who managed to escape by accident. In response, the Stodorani revolted against German overlordship and chased the Germans across the Elbe, but Gero was able to reverse this before Otto's arrival in Magdeburg later in the year. He subsequently bribed Tugumir, a baptised Slav prince, to betray his countryman and make his people subject to Germany. Soon after, the Obodrites and the Wilzes made submission.

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