A knight who, by magic, was made to resemble a Turk.
In The Turke and Sir Gawain, a later verse romance (c. 1500), Gromer, bewitched into the form of a “turke”, or churl, shows up at Arthur’s court and challenges one of the assembly to an exchange of blows.
After delivering one to Gawain, he asks to postpone the reciprocal strike. The turke then leads Gawain on a series of spectacular adventures, culminating in a visit to the Isle of Man, where Gawain, with the turke’s help, slays the pagan king and his giant attendants. The turke then asks Gawain to behead him, which results in his rebirth in the form of Gromer, a Christian knight. In the denouement, Arthur appoints Gromer the King of Man.
See also
Beheading Games | The Legend of King Arthur
Gromer Somer Jour | The Legend of King Arthur
Source
The Turke and Gowin | c. 1500