It has often (especially in earlier times) been considered the definitive lexicon for Old English.
This was written by Joseph Bosworth, who in 1858 became the Rawlinsonian Professor of Anglo-Saxon at the University of Oxford: the post was renamed in 1916 as the Rawlinson and Bosworth Professorship of Anglo-Saxon, in Bosworth's honour.
While being attributed to "J. Bosworth & T. N. Toller", this was a revision by Thomas Northcote Toller, based on Bosworth's 1838 dictionary, Bosworth's papers, and additions by Toller.
Thomas Northcote Toller issued a supplement in 1921.
Alistair Campbell issued an edition with "enlarged addenda and corrigenda" in 1972.