Mandalorians at last! "Clone Wars spoiler alert"

I'm not familiar with Montross(yet), so I honestly couldn't say. But I did a lot of reading yesterday at wookieepedia.com about Sabine Wren & that's how I knew anything about her past at all(haven't seen much of Rebels yet). Interesting woman.

Even Jango Fett was born on a Mandalorian world & seemingly "adopted" by them. Is anything known about the past of Montross? Wookieepedia may have some answers about him or maybe even Star wars.com.