alliances

i have alliances with other nations and we have a very good+ relations. will they help me out militray or economicly wise if im being attacked? lest say the mogols arrive would they just sit on their ass and i get invaded.

They'd help you if their forces are sufficiently strong to possibly turn the tide of battle, yes. Generally they will support you against your common enemy if they are nearby.

When I declared war on Portugal as the Scots, my allies, the Danes, sent a fleet all the way from Norway to the Iberian Peninsula and starting pirating Portuguese ships. :dizzy2:

Compared to the old M2TW, this was very unexpected. What is also unexpected is the fact that my allies don't backstab at every possible opportunity. I've been sharing borders with France and Denmark since the start of the game, and we've been allies since the start of the game, too. It's been about 350 turns now since the start.

:2thumbsup:

I've been finding alliances quite stable too; I came back to my French VM campaign after being annoyed by Empire and its problems (not to mention the shooting is not nearly as gratifying as hitting someone with cutlery), and my alliances with the HRE and the Poles are going strong. I almost feel guilty for not helping the HRE out with the nasty Milanese, but the whole point was to get a secure flank so I could wipe out the English, Scots and Danes. Now I guess I'll have to go after the Spanish and Portuguese, but it's looking as if I'll have to betray my allies in order to achieve my goals. I was just so used to being backstabbed that I'm amazed at the permanence of the alliances--well over 80 turns so far, last I looked.

I'll be interested in trying out a campaign as the Turks after I finish this one.

They are pretty stable. In general, unless you are a really weak ally and they don't like you much, they probably won't be backstabbing you. There is of course always a tiny chance they might, but generally not.
Playing an islamic faction is probably more difficult as your allies will backstab you if a crusade is called on you and they are catholic.