I'm working on a summer challenge for the Hallows prompt and I need some family background on the Gaunts.

Morfin or Merope: Who was the eldest child?

Why were Marvolo and Morfin sent to Azkaban?

I've been looking for the answers but haven't found anything yet. Perhaps my eyes just glazed over something entirely obvious, in which case I apologize sincerely, but I appreciate the help!