Marhault, Marhaus, Morholt
Malory gives four names for Irish kings. Two, Agwisance and Anguish, probably variants of a single name and to refer to the same man. The third Irish king is Ryons (Rience), also king of Norgales (North Wales), etc. The fourth is Marhalt.
Marhalt was the father of Sir Marhaus (according to Malory) and thus the father-in-law of King Anguish, who married Marhaus’ sister. The king is mentioned in Malory X, 66, fighting in the Lonazep tournament, but most of the time he remains in the background, perhaps busily governing his territory.
It is not usually mentioned in the Arthurian legends and romances that Marhalt was the father of Marhaus. In fact, Marhaus is usually portrayed as a separate character from Marhalt, who happens to be another Irish knight. Marhaus is also a formidable warrior and, like Marhalt, he is often sent by King Anguish to challenge other knights and kings to battle. Marhaus is best known for his role in the story of Sir Gawain, in which he is killed in combat by Gawain.
In some versions of the Arthurian legends, Marhaus and Marhalt are related, but their exact relationship is not always specified. For example, in the French romance La Mule sans Frein, Marhaus is said to be the nephew of Marhalt. However, in other versions of the story, they are simply portrayed as two separate knights from Ireland without any familial relationship.
The chronology of Malory is a little odd: When Marhaus fought Tristan he was the brother-in-law of the Irish King Anguish, yet only later does his father Marhalt, ascend the vacant throne. Marhalt’s sister, known as Isolde of the White Hands, is married to King Anguish. This makes Marhalt both a relative and a loyal subject of King Anguish.
Marhalt is seen as a knight from Ireland and is often portrayed as a fierce and formidable opponent in battle. In some versions of the story, Marhalt is sent by King Anguish to challenge the King of Cornwall to a duel over a dispute regarding tribute. In other versions Marhalt is sent to avenge the death of his brother, who was killed by Tristan, the nephew of King Mark of Cornwall. In either case, Marhalt’s relationship with King Anguish is an important part of his role in the Arthurian legends.
The family tree shows Marhalt’s descendants drawn from a variety of sources. One wonders if names such as Marhalt and Marhaus might preserve some genuine memory of the fifth-century King of Tara, Muircheartach I.
Source
Le Morte Darthur | Sir Thomas Malory, 1469-1470