Jacob Grimm, ed., Andreas und Elene (Cassel, 1840).
This is the editio princeps of the Old English poems Andreas and Elene. Both are uniquely preserved in the Vercelli Book.
Andreas is a poem about St Andrew's travel to, and 'adventures' in, Mermedonia, where he went to rescue St Matthew. The anonymous poet seems to have greatly influenced by Beowulf. On the other hand, Elene is one of the four signed poems by Cynewulf and is about St Helena's quest for the true Cross.
Other than the edited text and commentary, Grimm gives a quite long introduction (pp. iii-lviii), at the end of which he expresses his own view on Old English poetry, using a metaphor of the change of the seasons:
Solch ein herbstes aussehn hat mir die im heidenthum wurzelnde angelsächsische dichtung: nicht ohne matten widerschein setzt sie ihre säfte noch noch einmal um, und verkündet ihren nahen tod (p. lviii).
When printing Old English texts, Grimm adopted a peculiar spelling rather than copying the original spelling faithfully. He does not divide a- and b-verses by a blank space representing a caesura either. So his text in this volume looks rather different from Old English poetic texts in modern editions.
The latest edition of Andreas is Richard North and Michael D. J. Bintley, eds., Andreas: An Edition (Liverpool: Liverpool University Press, 2016), while the latest independent edition of Elene is P. O. E. Gordon, ed., Cynewulf's 'Elene' revised ed. (Exeter: University of Exeter Press, 1977).
The Vercelli Book or Vercelli, Biblioteca Capitolare CXVII.