How did Han meet Chewie?

Chewbacca was attempting to free Wookies being sold as slaves to an Imperial commander. When the Imperial found that Chewbacca successfully freed the slaves, he sent Imperial TIE Fighters lead by Lieutenant Han Solo to attack Chebacca's ship. Chewie was knocked unconcious in the process, but when Solo was ordered to kill him, he refused, arguing that the Wookie would be a useful slave. Chewie was rigorously worked by the Imperial commander, and was whipped frequently. Solo realized the cruelty of this and helped Chewbacca escape. The two then became smugglers and traveled the galaxy together until Chewie's death.