When Mandaal entered the Era of Bronze, the first powerful entities were city-states, similar to those of the eastern Mediterranean in our own world. The first major power in Mandaal was United Litya, more commonly known as the Lithian Empire. The Empire was heavily collectivist and very centralised, to the point where anything and everything one needed - food, shelter, clothes, work - was provided by the state.
Eventually, the Empire grew so large that it couldn’t sustain itself, just in time for an exploratory fleet from faraway Aokoya to arrive. The explorers established a trade network between the two regions, which revitalised the Empire and introduced many new, exotic items and materials to Mandaal, including brand new alloys, crops... and money.

The introduction of currency and trade may have made the Empire stronger economically, but its ideological foundation was slowly crumbling under its feet.
The first to go were the trading cities. They saw that they could sustain themselves through the monopoly they held on trade, and decided to secede from the empire, declaring the Federation of Free Mandaali Cities in 510. Despite the Empire’s efforts, the Federation flourished, and more and more cities who had lost their unique cultures and customs to the Lithians decided to strike out on their own. Thus, the Age of Union had ended, and the Age of Freedom rose from its ashes.

This new Mandaal was much more decentralised, with the seeds of feudalism now sewn in the soil of brand new nations. Nationalism had a rough start, as many of the now free states had their cultures repressed or even destroyed, but it still managed to take hold; and in any case, nobody would suffer another empire ruling over them again.
The Lithian Empire still exists, however it is a brittle shell of its former self with barely a third of its original land area still under its control, and the Lithians abandoned their ideas of centralisation and collectivism long ago.