In Greek mythology, Cratos ("strength") was a son of Styx and Pallas, brother of Nike, Bia and Zelus. He was the personification of strength and power. Cratos and his siblings were all companions of Zeus.
The spelling Kratos would be more faithful to the original Greek spelling, which is Κρατος.
... or Jordanis was a 6th century historian. He was an Ostrogoth and was a notary of Gothic kings in Italy. At the time of Justinian, he was a Christian and possibly bishop ...