"Nun freue dich, du Christenheit" (Now be joyful, you Christendom) is a Catholic hymn for Easter.
It goes back to a 1390 hymn, which later appeared as "Freu dich, du werte Christenheit".
The current hymn goes back to around 1390, when a Ein Mainzer Prozessionale (A Mainz processional, meaning a book of processional hymns) has a chant with the incipit "Disse oisterliche dage" (These Easter days).
The five stanzas appear as verses of the Marian antiphon "Regina celi letare".
A Breslau manuscript from 1478 lists three stanzas which are related to three stanzas of the Mainz source (1,2,5) but in reverse order, now beginning "Frew dich, alle Christenheit" (Be joyful, all Christendom).