These are all really interesting stories and I really appreciate the input.
The family were run out their stronghold in shame, drifing into poverty, disease and early graves. This explains the sudden move to a hovel in an unsavoury corner of Cyrodil when he was a boy. Determined to restore honour to his name, the orc decides to journey to Skyrim and make his mark looking for brave deeds to perform to build a real reputation similar to the false story he'd been told about his father - he'll work as a sellsword, look to help out random people against powerful foes or fight in the war - anything to make his mark and earn respect - but as himself, leaving the ignominy of his father's drug dealing ways and pointless death behind him - nobody needs to know about that.
I really like this because I like to believe that the orcs have a strong sense of pride and competition for prestige and honor. That's definitely something that might be interesting to fall on. I always find it hard to get my characters to accept a fetch quest or do a favor for someone because it wouldn't seem practical, even though I want play through that quest/misc objective. My character having to mentally make up for the faults of his family and redeem his honor seems like a good motive.
Why not something along the lines of your Character falling in love with someone from another clan, or species even, and his family finding it unacceptable. A feud started between the rival clans and your love was killed in the process, by a member of your family, so you left to come to Skyrim to start anew. You were distraught, drunk, you got into a fight with some Imperial Guards, hence your capture. As for your family, they're dead to you, but maybe not in the literal sense.
I always like a good dramatic story like this because it adds depth to the character. I'm beginning to flesh out my character and these suggestions are all really helping my decision making
