From Wikipedia:
Which is where last night's episode picked up. Octavian attacked Antony as Antony was attacking Brutus (again, not the "famous" Brutus).
Well, that & the right to rule Rome. He didn't like that Antony got that gig instead of him.
I would assume so, but they never make it back, as Antony & Octavian take the battle to them in Greece.