How to get Europa universalis 4 historical friends?

1. Maintain good diplomatic relations: maintain friendly relations with other countries and avoid war as much as possible. Diplomatic relations can be maintained by sending envoys, signing treaties and agreements, and exchanging gifts.

2.* * * Collaborate with the enemy: join other countries in the war and make positive contributions in it. This can increase mutual trust and goodwill, and may also become friends in history.

3. Improving relations: the value of improving relations with other countries through special events or decisions. For example, the success of cultural exchange, providing assistance to other countries and so on. Can bring about the improvement of relationship value.

4. Unity of faith: If two countries share the same faith, their goodwill will increase. You can achieve the unity of faith by preaching, changing the state religion and accepting immigrants.