I think it's taking place a century or two before Divine Divinity, which seems just slightly before the time of most of the people. But then again, Baud and Seth were in Divinity 2 and they had to have been pushing 90+ at the time, and Zandalor is over 700 years old in Divinity 2, so who knows.
I'm definitely interested in how this story will connect with Divine Divinity/2 , but I want to experience that for myself. There's a good chance that a lot of the things we do in this game will have echoes to the later games, though.