reunification

uudelleen yhdistyminen, uudelleenyhdistyminen The unification of something that was previously divided; used especially of a country.
2010, Greg Kucich, Keats, Shelley, and Romantic Spenserianism (page 273)

Many of Spenser's readers today find the cleavings and reunifications of Redcrosse and Una presenting a psychodrama of mental fragmentation (..)