Meliodas or Meliadus is a figure in Arthurian legend, famous as the father of Sir Tristan

Tristan

Tristan is one of the main characters of the Tristan and Iseult story, a Cornish hero and one of the Knights of the Round Table featuring in the Matter of Britain...

 in the Prose Tristan

Prose Tristan

The Prose Tristan is an adaptation of the Tristan and Iseult story into a long prose romance, and the first to tie the subject entirely into the arc of the Arthurian legend...

 and subsequent accounts that draw material from it, including the Post-Vulgate Cycle

Post-Vulgate Cycle

The Post-Vulgate Cycle is one of the major Old French prose cycles of Arthurian literature. It is essentially a rehandling of the earlier Vulgate Cycle , with much left out and much added, including characters and scenes from the Prose Tristan.The Post-Vulgate, written probably between 1230 and...

, Malory

Thomas Malory

Sir Thomas Malory was an English writer, the author or compiler of Le Morte d'Arthur. The antiquary John Leland as well as John Bale believed him to be Welsh, but most modern scholars, beginning with G. L...

's Le Morte d'Arthur

Le Morte d'Arthur

Le Morte d'Arthur is a compilation by Sir Thomas Malory of Romance tales about the legendary King Arthur, Guinevere, Lancelot, and the Knights of the Round Table...

, and the Compilation of Rustichello da Pisa

Rustichello da Pisa

Rustichello da Pisa, also known as Rusticiano and Rustigielo , was an Italian romance writer best known for cowriting Marco Polo's autobiography while they were in prison together in Genoa. A native Pisan, he may have been captured by the Genoese at the Battle of Meloria in 1284, amid a conflict...

. He was king of Lyoness, and sometimes considered a vassal of King Mark. The exploits of his youth are recorded in his own romance, Meliadus, which forms part of the Palamedes

Palamedes (romance)

Palamedes is a 13th-century French Arthurian prose romance. Named for King Arthur's Saracen knight Palamedes, it is set in the time before the rise of Arthur, and relates the exploits of the parents of various Arthurian heroes...

and Rustichello's Compilation. His first wife, Tristan's mother Isabelle, was Mark's sister, and his second wife was a daughter or sister of Hoel

Hoel

Hoel or Howel is a legendary king of Brittany and one of the oldest characters associated with Arthurian legend. He is the son of King Budic of Brittany, and serves as one of King Arthur's vassals and loyal allies...

 of Brittany

Brittany

Brittany is a cultural and administrative region in the north-west of France. Previously a kingdom and then a duchy, Brittany was united to the Kingdom of France in 1532 as a province. Brittany has also been referred to as Less, Lesser or Little Britain...

.

Meliodas was the second king of Lyonesse according to the late Italian romance Il dui Tristani. He was the son of Felec

Felec of Cornwall

Saint Felec or Felix of Cornwall was an obscure 5th or 6th century British saint active in the country's south-western peninsula. Saint Felix was said to have had the miraculous gift of being able to communicate with lions, cats, and other feline creatures. The church at Phillack, near Hayle is...

 and married Isabelle, daughter of King Meirchion

Meirchion

Meirchion was the father of King Mark of Cornwall, famous for his role in the story of Tristan and Iseult. He is thus assumed to have been an ancient king of Cornwall who reigned in the late 5th century, however the name of Mark's father derives from Old Welsh sources in which Mark is associated...

 of Cornwall

Cornwall

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

.