European Union

The European Union (EU for short) is a politico-economic union consisting of various countries in Europe.

Background
For some time prior to the events of the British Halloween, the Roman Catholic Church manipulated the member countries of the EU council into making "attacks" on the United Kingdom, starting with a treaty that banned the UK's nuclear weapons and required them to give up their nuclear arsenal to France, with the official reason being so that France would be the sole possessor of nuclear weapons in the EU and therefore have the technology to safely disassemble them. With Queen Elizard's reasoning that they need not react to such clear provocation, the other countries continued to take them lightly and act as they pleased, which contributed to Carissa's decision to carry out a coup d'état.

Tree Diagram Remnant Arc
Several EU countries were among those that launched spacecrafts in an attempt to retrieve the remains of the destroyed Tree Diagram.

Toaru Majutsu no Index: Road to Endymion
The EU was one of many groups which put together projects for the Venus Probe Contest by way of the EU Space Industry Committee.

Hawaii Invasion Arc
The EU was planning to dispose of their golden rings and bones via the Atlantic Ocean, but they did not have enough sources of funds to cover it.

Coronzon Arc
During the Crowley's Hazard invasion of the United Kingdom, Aleister Crowley remarked that if he gathered all of the assets he had hidden around the world, he could probably buy up the entire EU after it had declined following the back-to-back conflicts of the British Halloween, World War III and the Magic God Siege in Denmark.

States

 * Austria
 * Belgium
 * Czech Republic
 * Denmark
 * Finland
 * France
 * Germany
 * Italy
 * Poland
 * Portugal
 * Romania
 * Slovenia
 * Spain
 * United Kingdom

Trivia

 * As of June 2016, the real world United Kingdom has voted to leave the European Union in a referendum.