Sometime in the 1500s the two Muiscan Kingdoms under the Zipa and the Zaque went into a civil war. In a situation similar to that of Isabella I of Spain the daughter of the Zaque secretly wed the son of the Zipa uniting the two Kingdoms against their fathers' wills. The Zipa, which had a much stronger army threatened to destroy Hunza if the Zaque tried to rid himself from the bond of Father-in-law to the Zipa's son. So the two Muiscan Kingdoms were unified and the start of the Muiscan Union began.
The Muiscas spread across the region of OTL Colombia, Panama, Venezuela, and Costa Rica.