Looking for online persistent turn based strategy game Suggestions?

I'm hoping the community might be able to suggest some games for me to play with my friends. I live far from my friends and in a different timezone. I'd love to play something like Axis and Allies or Risk online with friends. The caveat is that it needs to be persistent so that we don't need to all be on sitting there to play. 2 player support is fine but it'd be better if it could handle more.

Browser based, Windows, or iOS all would be fine.

Thanks reddit for helping me stay connected with my friends!