How am I supposed to get 500 diplomatic tribute from the Berbers?

[Riekopo]

I'm playing The Last Roman as the Expedition and I don't understand how I'm supposed to get this money from them. They hate me.

[Jezza93]

I'd be surprised if it is even possible. In my experience AI never give money as a gift and only when they want something. You can't offer them trade agreements or much at all. They don't want an NAP because they don't consider you a threat in strength ratings at that point. I'd imagine it could theoretically be possible if you declared war on them and destroyed all their armies in one big battle. But even then it's unlikely and alot of effort.

Perhaps if you went separatist you could manage it.

[Caligula's_Horse]

I've had two playthroughs, and managed it in both in rather different ways. The first time I just lucked out with the Berber's leader, who was more or less friendly right out of the box (not sure if I got lucky with their initial leader, or if I got lucky when their leader took a dirt nap fighting the Visigoths or something and got replaced by a friendlier one). Just asked for the money and they gave it.
My second separatist play through the Berbers hated me, but eventually warmed over when I convinced them to pick a fight with the Vandals (really helps ease the pressure, and you'll be feeling a lot of pressure going separatist), after which they were friendly enough, and again just gave me the money when I asked.

Perfectly fine to just skip the whole thing though. The extra cash you get for completing chapter objectives is negligible.

[6Bagheera9]

Actually if you have really friendly relations with a faction or are vastly more powerful but not hostile, you can just for a payment and if its not too large they will often give it to you. In a Langobard campaign I holding back the Hunnic hordes and stomping one stack after another. Almost everyone loved me for beating on Attila, so when my economy started to creak under the strain I was able to pass the hat around and raise several thousand in subsidies. They wouldn't cough it up turn after turn, but most were willing to chip in once and a while.