You are playing with Spain, right?
Well, people usually attack you in Total War games so get used to it.
If everyone is attacking you there are some interesting tactics to use.
First:
Be the pope's best friend.
Get a diplomat at Rome right away and start giving him money, maps, help against rebels or whatever enemies they have. If you manage to make an alliance with him, its even better as it will often result in excommunication for your enemies.
Second:
Concentrate your forces at good defensive positions.
If you are playing at Iberian Peninsule, there are two main entrances: Gibraltar at the south and the Pyrenees at the northeast.
You can use a game exploit and block the land passage with your navy. Place forts at montain passages or build watchtowers and keep a strong army nearby. Use brigde points as natural forts, you can defend them with a couple of spearmen and some archers against a full stack(remember to use schiltrom formation).
Third:
Improve your economy.
As some wise man once said(don't remember who): "Wars are won by money", make this one your motto if you are planning to sustain a long and difficult war against your enemies. Full stack armies cost money, so, get trade agreements with everyone you are not at war and improve your ports and markets at your safest cities.
Fourth:
Make your enemies regret they are your enemies.
Get a full stack with a good general with high dread and decide that his holliday trip will be across the Europe. Don't attack your enemies biggest armies, aim for their greatest cities and sack, sell all improvements and go for the next target, this will not only make you rich but will also break AI's economy making hard for them to keep good armies at the field.
Fifth:
Expand your territories.
Once your enemies' main forces are out of combat, just move those defensive stack foward to your new frontiers.
Sixth:
Be faster than your enemy.
Just use askthepizzaguy's motto: "Blitzing is the key"
Seventh:
Forget your reputation.
Unless your are aiming for a chivalric game, where you are friends with everyone ignore this, but if not, make them hate you as long as they fear you.
8th:
Kill their leaders.
No army can keep fighting without their leaders, kill them with assassins or use a kamikaze stack of light cavalry and aim them at their general. That will usually kill him and make the rest of their forces to rout.
9th:
Force them to retreat.
AI will often retreat if their capitol is under siege, just send a small battalion and make a fake attack to force them to go back, when their armies come after you, just hide in the woods and wait to ambush them, you can just flee for you live if want.
I think that is nice for a start.

Oh, I also recommend you set difficulty to VH/VH as AI will be much more interesting but not necessarily more difficult.
Bookmarks