As on 1 January 2020, some three percent of the population of the EU were citizens of one member state living and/or working in the territory of a member state other than that of which they are a citizen. In addition, around five percent of the resident population of the EU consisted of third country nationals. Naturally, these diasporic groups formed cross-border couples consisting of partners of different nationalities or partners of the same nationality both living in a country other than that of their origin. This reality, to be sure, raises many legal questions for the persons involved where the national family laws of several countries come into play. In an effort to bring about added legal certainty and predictability to couples in cross-border situations, the EU adopted several instruments often referred to together as EU private international family law.
