TOP  Military  Declaring War

Once you've increased provisions and soldiers with strategy phase, it's time to start thinking about how to defeat other clans.
When you declare war on a neighboring country, send in soldiers, and capture a base, you can make that base yours.

Declare war and war status

If you carry out the Strategy Phase command "Declare War", you will enter war status. While in war status, you will be able to march on counties and bases of the clan you declared war on.

Clans you cannot declare war on

Clans you are already at war with
Clans you are in an alliance with or vassal clans. (If you use "Dissolve", you will be able to declare war.)
A clan whose side you have chosen or who has chosen your side.

Dissolve 

Choose side

When you "Declare war", other clans may choose to side with you or your opponent.
Clans who have chosen your side may send gold, provisions, muskets, or horses to support your battle.
The enemy's camp is made up of the enemy army and anyone that has sided with it. Even though they are in the enemy's camp, you cannot march on a clan who has only sided with your enemy. If you must march on them, you will need to "Declare War" on them as well.

If a battle occurs nearby

If a battle breaks out nearby, you will sometimes be asked if you will side with one of the participants. Doing so will raise the Opinion that clan has of yours. Refusing to side with a clan that you are allied with will likely lower their opinion of you.
Note: Even if you side with one of them, unless they declare war on you, there is no worry of them attacking and invading you.

Aggression

Aggression is a gauge of how much the people and soldiers desire this battle. If aggression is high, castles become harder to defeat during castle defense, and in battle, each units' morale starts higher.
During battle or castle defense, fulfilling the following conditions will raise aggression greatly. You should push the attack when aggression is high.

Conditions

Conditions for raising aggression

Gain victory over a clan whose rank is greater
Gain victory over a clan whose soldier numbers are greater
Gain victory over a clan with high aggression
Gain victory in a battle where both armies have lots of soldiers.
After dealing a great deal of damage to an enemy unit.

Reinforecement Request

You can request reinforcements using "Reinforcement." The selected base will send you back-up.
The reinforcements can be selected as a unit upon marching.
The request is easier to be granted by clans you are allied with or whose Opinion of your clan is high. Any clans that are vassals of yours will send forces.

The end of war status

War status ends when peace is established or when one of the clans is wiped out. You can negotiate for peace using Strategy Phase command "Negotiations" - "Peace".

Negotiate