The Ancients had World Meetings too, but things were a little different.
Most of the Ancients wouldn't show up if they were in some kind of issue, like a time of war or a famine.
The ones who showed up the most would come to be the four canon Ancients of Hetalia.
Like the modern nations, they had a really hard time having a meeting going anywhere. Most of the time, Britannia would use magic to stick everyone to their chairs and wouldn't let them go until the meeting was over.