Sir Gawain is recorded as a 'Grail knight' along with Sir Lancelot and Sir Percival, but it depends which writer you read as to who attains the mystical 'Holy Grail'. The earliest successful knight recorded is Gawain, but he fades from prominence in later stories like the 'Didot Perceval' in which he fails to attain the Grail but witnesses an interesting vision in the light of our Mersey researches. As summarised by John Matthews the story goes:

".... passing onwards to other lands. He (Gawain) comes upon a fountian with a vessel of gold fastened to it by a chain of silver. A statue carved on one of the pillars speaks, foretelling that Gawain is not the one to be served by the vessel." "He sees a priest approach, then three maidens in white come, one carrying bread on a dish of gold, one carrying wine in a vessel of ivory, the third bearing meat in a dish of silver. They leave their offerings at the fountain and depart. 'But as they went, it seemed to Sir Gawain that there was but one of them, and he wondered much at this miracle.'"
 

 
Three aspects flow into the same river (Mersey) - but where was the fountain with the grail located and where is it now ?

In the final battles between the knights of the divided round table Gawain receives a mortal wound in combat against Lancelot during fighting in France. The wound opens on Gawain's return to fight Mordred with Arthur in Britain and he dies from it having engraved on his tomb the words:

"HERE LIE GARETH AND GAWAIN, WHOM LANCELOT KILLED THROUGH GAWAIN'S FOOLISHNESS"

In some traditional writings it is Gawain that obtained sovereignty for King Arthur which explains Arthur's lament in the 'Alliterative Morte Arthur':

"Then the valiant king looked and was sad at heart, groaned dreadfully, with tears of grief, knelt down by the dead body, and caught it up in his arms, lifted up his visor and kissed him quickly, looked on his eyelids that were tightly closed, his lips like lead, and his pale countenance."

"Then the royal monarch cried aloud, 'Dear kinsman by blood, I am in sorry plight. For now my honour has departed and my struggle is ended. Here lies the expectation of my well-being, my success in battle. My courage and my valour stemmed wholly from him, my counsel, my succour that sustained my spirit. The king of knights in Christendom, thou wert worthy to be king, though I wore the crown. Mine good fortune, my good name on earth were gained through Sir Gawayne, and through his wisdom alone. Alas, now my sorrow increases. I am utterly destroyed in mine own land. Ah, treacherous, cruel Death, thou lingerest too long ! Why dost thou hold back ?" (Translation by J.L.N. O'Loughlin).
 

 
As a post script to Gawain's story William of Malmesbury writes in his 'De Gestis Regum Angelorum' (Deeds of the Kings of the Angles 1125 AD) that:

"At the time (1066 AD to 1087 AD) in a province of Wales called Ros (Pembrokeshire) the tomb of Walwein (Gawain) was found who, by no means unworthy of Arthur, was a nephew by his sister. He reigned in that part of Britain still called Walweitha, a soldier greatly celebrated for valour, but driven from the kingdom by the brother and nephew of Hengist (about 450 AD), of whom I spoke in Book I, he made them (the Saxons) pay severely for his exile." (Translated by L.B. Hall in 'The Knightly Tales Of Sir Gawain' 1976).

Four hundred years later William Caxton noted in the introduction to his 1485 AD edition of 'Morte D'Arthur': "Item in the castle of Dover ye may see Gawaine's skull, and Cradok's mantle: ...." Sir Gawain's age is given at the time of his final conflict against Lancelot as 76 so he was 76 or 77 at the time of his death.
   
  Arthur's Wales & Burial Place of Sir Gawain - Ros Pembrokeshire

 
It is an interesting observation that 'WALWEITHA' must break down to 'WALWEI-THA', the region or 'THA' of Walwein. Using this break down as a model there is a marked resemblance to the name of Warrington in use during the same time period 'WALINTUNE' (Domesday 1086 AD). 'WAL-IEG-TUN' could equate to 'WAL-(W)EI-THA', 'TUN' probably equating to 'THA' in meaning.

This presents intriguing possibilities in the light of our present explorations into the Mersey Valley but will probably remain forever conjectural. Are we now still living in the lands of Sir Gawain ?

In 'Gawain And The Green Knight' we have, enshrined by a Cheshire monk, the entire yearly fertility cycle of the Mersey and its geography placed in a frame work of Celtic legend and yet made palatable for a Christian Medieval audience, most of whom would not appreciate the full significance of what they were hearing. It is unmistakably a later continuation from the early Celtic religious patterns and beliefs of North West England and the river Mersey.

"Peace makes a good man perform good works; for all men are better and the land is merrier."