Citizen of the Galaxy — Robert A. Heinlein

SLAVE
Brought to Sargon in chains as a child -- unwanted by all save a one-legged beggar -- Thorby learned well the wiles of the street people and the mysterious ways of his crippled
master...

OUTLAW
Hunted by the police for some unknown treasonous acts committed by his beloved owner, Thorby risked his life to deliver a dead man's message and found himself both guest and prisoner aboard an alien spaceship...

CITIZEN
Unaware of his role in an ongoing intrigue, Thorby became one of the freest of the free in the entire galaxy as the adopted son of a noble space captain ... until he became a captive in an interstellar prison that offered everything but the hope of escape!