The European Court of Justice ruled that all European Union countries must grant residency to spouses of EU members in a ground-breaking decision.

Adrian Coman, Romanian, and his American partner, Clai Hamilton have been fighting the case since 2016.

Romania, where same-sex marriage is not legal, ruled that Hamilton’s residency would not be recognised because the couple’s marriage is not considered legitimate by the state. The couple appealed the decision to the Romanian constitutional court where the case was then referred to Luxembourg.

The ECJ ruled on Tuesday that Hamilton does have residency rights in Romania regardless of the state’s own marriage laws. The purpose of the EU is to allow free movement of individuals, also applying to marriage. The court determined that all member countries must respect the rights of married spouses regardless of gender or sexuality.

Law in the EU states that a non-EU spouse of EU citizens may join the European nation in the member state where they reside. However, Romanian law doesn’t identify gay or lesbian marriages as “spouses”.

The ECJ ruled that “spouse” is a gender-neutral term. It was also determined that there was no justification for rejecting the free movement of the couple within an EU country.

European Union countries retain “the freedom whether or not to authorise marriage between persons of the same sex, they may not obstruct the freedom of residence of an EU citizen by refusing to grant his same-sex spouse, a national of a country that is not an EU member state, a derived right of residence in their territory,” according to the ECJ.

Only six states in the EU do not legally recognise gay marriage: Romania, Poland, Slovakia, Bulgaria, Lithuania and Latvia.

The ruling allows couples to have their rights of free movement guaranteed regardless of their sexual orientation. This decision is a huge success for same-sex couples and families as they no longer have to fear separation within the EU due to immigration or residency laws.