Khasekhemwy in Egyptian also
Beb(t)y, Djadjay
Kheneres in Greek
Khasekhem(wy) was a military commander under king Peribsen. When he came back from crushing an upraising in Nubia he is thought to have challanged his master and likely took the lead more or less by force. Later he changed his name with an additional -WY meaning two powers, not one, and put both Horus and Set to his name as a neutral gesture in the struggle between supporters of the two gods.
He has left statues of himself sitting on the throne (in the picture left) and was buried in an unusual tomb at the old royal cemetery in Abydos, the last to be built on this site. It's a construction with a resem-blance to the northern style mastabas though more streched out. He is also likely the builder of a great enclosed area (called Gisr el Mudir) at Sakkara 600 meters west of Djoser's complex. It's a wall made of crudely cut stone, the first of its kind in history. (More about it in the main text thru the link below).
(Khasekhemwy main text)