How to make those bastards serve me?

[Askthepizzaguy]

WHAT are the benefits of having a vassal?

What exactly do you get in return that could possibly equal their actual territory?

[Monsieur Alphonse]

WHAT are the benefits of having a vassal?

What exactly do you get in return that could possibly equal their actual territory?

Their territories are added to your total. Which means that if you are blitzing you can conquer regions without actually capturing them. And you get most of their money.

[Askthepizzaguy]

Pizzaguy no like. Bad Medicine.

Their "alliance" can be broken and you will be at war with them again. I've become a vassal before and backstabbed my lord.

Besides, what good is peace and prosperity when we can build a glorious new future on the broken bodies and charred corpses of the vanquished?

[Jedi Bruno]

Perhaps one thing good is that you can get some unique buildings if you have enough patiance

[Askthepizzaguy]

Are you threatening me, Master Jedi?

No, seriously that's perhaps the best reason I've been given so far. Much like Rome, where you could get excellent Scipii temples if you conquered them late. Getting the best temples from each faction allowed diversity in construction.

A pity your empire needs to be one religion. I'd love to see Orthodox cathedrals, Catholic cathedrals, and Islamic Mosques as well, all coexisting in the same town and offering a religious tolerance public order bonus to offset the religious penalty for not having a state religion.

[Jedi Bruno]

Yes, in Rome that was a good thing really. I usually awaited for maceddon to build temple of artemis at their cities to give my greek armies a good archer support.
In medieval I don't know all the unique buildings you can get, but scotland's castle library is a nice building.

[Veho Nex]

Besides, what good is peace and prosperity when we can build a glorious new future on the broken bodies and charred corpses of the vanquished?

In my sig now

[Askthepizzaguy]

In my sig now

I didn't know you had a sig. I thought you were an autonomous collective.

Spoiler Alert, click show to read: 

DENNIS:
You're fooling yourself. We're living in a dictatorship: a self-perpetuating autocracy in which the working classes--
WOMAN:
Oh, there you go bringing class into it again.
DENNIS:
That's what it's all about. If only people would hear of--
ARTHUR:
Please! Please, good people. I am in haste. Who lives in that castle?
WOMAN:
No one lives there.
ARTHUR:
Then who is your lord?
WOMAN:
We don't have a lord.
ARTHUR:
What?
DENNIS:
I told you. We're an anarcho-syndicalist commune. We take it in turns to act as a sort of executive officer for the week,...
ARTHUR:
Yes.
DENNIS:
...but all the decisions of that officer have to be ratified at a special bi-weekly meeting...
ARTHUR:
Yes, I see.
DENNIS:
...by a simple majority in the case of purely internal affairs,...
ARTHUR:
Be quiet!
DENNIS:
...but by a two-thirds majority in the case of more major--
ARTHUR:
Be quiet! I order you to be quiet!

Honestly, that does sound like a good sig. Just be sure to quote the source.

[Old Geezer]

IIRC sacking or even exterminating a city of a faction which is excommunicated doesn't cause a drop in diplomatic reputation; nor does assassinating opposing religious faction (or rebel) characters or sacking/exterm. their cities.

[Yoyoma1910]

Try offering it as an alternat offer next time some ASKS YOU for a cease fire. That tends to be when you'll be able to get vassalage in my experience.

I like to keep other countries around, albeit often in smaller forms, because it helps with my trade economy, which allows me to maintain an expensive army.