Sonbef [SEP] father
can be a double name, but can also be a filiation "Son of Amenemhat Sonbef", which both Ryholt and Baker see as evidence that Sonbef was a son of Amenemhat IV and a brother of Sekhemre Khutawy Sobekhotep, the founder of the 13th dynasty. Thus, they see Sonbef and Amenemhat V as two different rulers, an opinion also shared by Jürgen von Beckerath. Ryholt and Baker further posit that Sonbef's and Amenemhat's rules were separated by the ephemeral reign of Nerikare, while von Beckerath believes it was Sekhemre
Sonbef
Mehibtawy Sekhemkare Amenemhat Sonbef (also Amenemhat Senbef) was an Egyptian pharaoh of the 13th Dynasty during the Second Intermediate Period. According to egyptologists Kim Ryholt, Jürgen von Beckerath and Darrell Baker, he was the 2nd king of the dynasty, reigning from 1800 BC until 1796 BC.
Identity.
There is a debate between egyptologists on whether or not Sekhemkare Sonbef is the same king as Sekhemkare Amenemhat V, 4th ruler of the 13th dynasty. Indeed, Sonbef called himself "Amenemhat Sonbef"; this