In Malory Book III, chapters 5 and 12, Sir Hontzlake of Wendland comes into Arthur’s court at the Round Table’s first feast, and forcibly abducts Nimue, who has not yet become an enchantress and who has ridden into court to claim a stolen brachet. King Arthur assigned King Pellinore to retrieve the lady and bring back the knight. Pellinore pursues them and came upon Hontzlake who fought Nimue’s cousins, Mellot of Logres and Bryan (this might be the same character as Brian of the Isles).
Pellinore challenged Hontzlake to combat and the latter killed Pellinore’s horse, which enraged the King so much he killed Hontzlake with a single blow to the head and returned Nimue to Camelot.
In Malory Book IV, chapters 7 and 8, the name Ontzlake appears, this time attached to the good brother of the evil Sir Damas. Here Sir Ontzlake keeps a fair manor through
prowess of his hands ... and dwelleth [therein] worshipfully, and is well beloved of all people.
Le Morte Darthur | Sir Thomas Malory, 1469-1470