Most notable, (Arminius) was the unifier of the early Germanic tribes against the Roman Empire.
Its early name relationship to Arminius (who was German born and educated in Rome) was discovered by Martin Luther.
Arminius himself is said to have descended from the lower German tribes on coastal Germany who many originated as fisherman from the British Isles.
Spelling variations also include Hardman, Hartman, Hartmande, Hermande, Hartmann, Herman, Larmande, Armande, Arman, Armmand, Hermman, Larmand, Ehrman, Ehrmann, and Armand.
This is not surprising as Arminius unified the German tribes and drove the Roman army into submission.