What does influence do?

[HalfThere]

Apart from making populations governed by a high-influence family member happier, what effects does influence have in-game?

[lt1956]

I believe Elections for the romans are more common for those with higher influence. Small bonuses here and there, some not even documented I am sure.

[Marie Louise von Preussen]

Diplomats with high levels of influence can make more favourable deals to you, and it is cheaper and easier to bribe an enemy army or character with them.

[John I Tzimisces]

When you get a new faction leader, the guy with the largest amount of influence becomes your faction heir. I think it also adds to the size of bodyguard units and maybe security...

[Ulf]

When you get a new faction leader, the guy with the largest amount of influence becomes your faction heir.

what if two or more tie?

[John I Tzimisces]

what if two or more tie?

I believe it goes to the older one, as it would in realistic succession anyhow.

[shadowarmy75]

I believe influence also affects how far the affect of your general's command stars in the field is.

Example:0 influence

___PPPPPPPPPPPPPPPPPPP___
___________GG____________

In this case only the ones next to the general gets the bonuses but if he had 5 influence:

___PPPPPPPPPPPPPPPPPPP____]
__________GG____________

[Shaun]

Influence also maked governers keep order in cities easier. for every +1 influence your govener has it adds +5% to happiness in cities.

[Marcus Scaurus]

It would be great if the influence of the faction leader/heir in the region influences diplomatics. For example, I'm Macedonian and my very influencal faction leader marches north to finish off the last Dacians. His nearby presence and influence will make the Dacians ask, or even beg, for a ceasefire, also making it easier to make them a protectorate. If your faction leader has almost no influence and/or command stars, other factions should be less enthustiastic to alliance with you or to stop a war.