Milos Columbo was a Greek smuggler and arch-enemy of Aristotle Kristatos. Initially he was suspected of being the man who hired Emile Locque to kill Timothy and Iona Havelock, and thus James Bond's enemy. However after Locque killed Columbo's lover Lisl Von Schlaff, Columbo was able to convince Bond that he wasn't Locque's master; Kristatos was.
He proved it by leading a raid on one of Kristatos' warehouse, allowing Bond to kill Locque in revenge for the murder of Luigi Ferraro. After this, Bond trusted Columbo completely. Columbo's men subsequently aided Bond and Melina Havelock in their raid on Kristatos' mountain stronghold. Columbo and Kristatos wound up in a struggle to the death, wherein Kristatos wounded the Greek badly. However, Columbo recovered in time to throw the knife that ended Kristatos' life, saving Bond and Melina. He later recovered from his injuries.