- "Baz doesn't want to register anywhere... Up until now, Baz is something I thought impossible on Beta Colony. He's a man who isn't here. He's passed across the information network without a blip. He never arrived -- never passed through Customs, and I'll bet that was one hell of a neat trick -- as far as the computers are concerned, has not eaten, or slept, or purchased -- or Registered, or been Carded -- and he would rather starve than do so."
- ―Miles explains Baz to a Betan[src]
Bazil Jesek had been a Barrayaran military engineering officer with the rank of Lieutenant until he deserted in the heat of battle. He spent the following years on the run from Barrayaran Service Security; if he ever got caught, he would be sentenced to death by quartering.
He met Miles Vorkosigan while hiding in a recycling facility on Beta Colony; Miles hired him to serve as engineer on the RG 132 ship he'd recently acquired. In the course of shipping their first cargo (running weapons past a blockade to a country on Tau Verde IV), he ended up taking Bazil Jesek as an armsman and giving him the rank of Commander in his imaginary mercenary fleet. When the fleet became real, Bazil was promoted to Commodore and placed as a co-commander of the fleet. He married Elena Bothari and the two stayed on as Dendarii officers for more than a decade.
The couple eventually retired from the Dendarii and from Miles' service; they settled on Escobar and began raising a family.