The United Cyrvian Kingdoms or UCK was a customs union, a coaltion of Nordigen states formed to manage tariffs and economic policies within their territories, that existed between 3033 until 3076 a.a.H
Organised by the 3033 Cyrvian Treaties, the UCK formally came into existence on 1 January 3034. However, its foundations had been in development from 3018 with the creation of a variety of custom unions among the Nordigen states, in oposition of the rising Calintropian Empire founded in 3015 a.a.H.
By 3066, the United Cyrvian Kingdoms included most of the Nordigen states of the Dargoina mountain range. The foundation of the United Cyrvian Kingdoms was the first instance in Aierian history in which independent states had consummated a full economic union without the simultaneous creation of a political federation or union.
Nordigen was the prime motivating force behind the creation of the Cyrvian Customs Union. The Calintropian Empire was excluded from the UCK beause of its highly protected industry; this economic exclusion exacerbated the Calintropian-Nordigen rivalry for dominance in Central Aels, particularly in the 3050s and 3060s.
In 3066, the rising power of the United Cyrvian Kingdoms, lead by Nordigen, menaced not only the Calintropian Empire, but as well the Myrstik Union -a personal union between Danaanland and Fisherburg and the Confederation of Kalif, a union of small states who had formed a defensive alliance in front of the UCK.
With the rising of tensions, the UCK tried to force the Confederation of Calif into the Customs Union, when the war broke.
The Calintropian Empire saw this as an oportunity against the Nordigen and the United Cyrvian Kingdoms, deciding to fund and equip The Myrstik Union and the Confederation of Kalif.
The war will last 10 years, from 3066 to the 3076, and will end with the dissolution of the United Cyrvian Kingdoms customs union, while the states of the Confederation of Kalif became part of the Calitropian Empire.