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.

Erno Gero (born Erno Singer; 8 July 1898 – 12 March 1980) was a Hungarian Communist Party leader in the period after World War II and briefly in 1956 the most powerful man in Hungary as first secretary of its ruling communist party.