Celtica

Formation
In 2019, the Scottish finally gain their independence, with 52% voting to leave the UK. Soon, however, due to poor diplomatic relations with the rest of the UK, Scotland's economy began to decrease in prosperity, prompting them to begin an alliance with its neighbour Ireland. Scotland was given some economic help when it joined the New European Union (which was formed as a military and economic counterpart to the EU due to Brexit) in 2027. Ireland launched a full scale invasion of Northern Ireland and eventually Wales in 2033, with help from Scotland. It was successful, and with little resistance from England, the Democratic Monarchy of Celtica was formed on 11th June 2034, as the new superpower in the British Isles.

Early History
Celtica's diplomatic relations soon turned sour when they refused to take in refugees from a series of terrorist attacks in English cities during the late 2030s. However, due to their Celtic roots, a good relationship was maintained with Scotland. But even the Scottish prime minister cut all ties with Celtica in 2040 after the recently crowned King Cian forced the nation into an isolated, totalitarian state, similarly to the now-dissolved Democratic People's Republic of Korea.

2051 - Dissolution
In 2051, Celtica launched a full-scale invasion of Scotland, and completed it in 2 short months. In 2053, a rebellion rose in Ireland's Shannon region and for a fortnight, the Republic of Shannon was a legitimate country. In the Republic of Shannon's first election, a party that was in favour of becoming reannexed by Celtica rose to power. The first and final legitimate action of the Republic of Shannon was to join to Celtica. The nation was rather dormant for the next 34 years, aside from the establishment of a colony on the moon in 2079. Notably, in 2087, the public was not informed the King had actually perished on an overseas venture to maintain relations in Africa. In 2097, a group of intellectual children on the island of Anglesey questioned the fact that King Cian had been ruling for 57 years, as it was taught in local schools that King Cian was 60 when his rule began. This lead to the bloodiest conflict in Celtica's history: the Battle of Llanfair, when 125,000 residents rebelled, and only 700 were believed to have returned home. After England reclaimed Wales and Northern Ireland in 2097, the government surrendered, and the borders of 2019 were reinstated.