Family reunification refers to the establishment of a family relationship which is either (a) the entry into and residence in a Member State, in accordance with Council Directive 2003/86/EC, by family members of a third-country national residing lawfully in that Member State ("sponsor") in order to preserve the family unit, whether the family relationship arose before or after the entry of the sponsor; or (b) between an EU national and third country national established outside the EU who then subsequently enters to the EU (EMN Asylum and Migration Glossary, p.70)