Sir Gawaine represents the knightly virtue of Mercy in a strange tale in which he fought a knight who had killed Sir Gawaine's hounds, after they had slain that knight's white hart.

'Why have you slain my hounds?' said Sir Gawaine. 'For they did but their kind.' And he smote the knight so hard that he fell to the earth, and then he cried mercy and besought him as he were a knight and a gentleman to save his life. Sir Gawaine would no mercy have, but unlaced his helm to have stricken off his head. Right so came his lady out of a chamber and fell on him, and so he smote her head off by misadventure.
- Malory

Gawaine returned to Camelot with the lady's body on his horse, and her head hung about his neck.

And there by ordnance of the queen it was judged upon Sir Gawaine for ever after he should be with all ladies, and fight their quarrels, and that he should never refuse mercy to him that asketh mercy. Thus was Gawaine sworn upon the four Evangelists.
- Malory

Prince Albert made frequent visits to the Robing Room to view Dyce's progress. His active interest in and support of the fine arts schemes in the Palace of Westminster could express themselves in both criticism and praise.

Additional Information on
Mercy - Sir Gawaine swearing to be merciful and 'never be against Ladies'

The five frescoes in the Robing Room represent the chief virtues of Chivalry: Courtesy, Mercy, Religion, Generosity and Hospitality. Dyce was actually commissioned to produce seven frescoes and seven friezes in the room, for the sum of £800 per year. The Arthurian tales - chiefly in the 15th-century version by Sir Thomas Malory - had long been recognised as a founding heroic myth of the British nation and as such, were felt to have an important place in the decoration of the new Palace of Westminster.

The actual historical period to which Arthur would have belonged is from late-fifth to early sixth centuries AD - that is, around 475 to 511 or 539 AD - and he and his so-called 'knights' would probably have worn arms and clothes of the late Roman Empire.

However, the tales have come down to us in medieval guise, largely through the version by the 15th-century Sir Thomas Malory, and even today, when we really know better, we see Arthur and his knights in full medieval dress: chain mail, helmets, saddles and stirrups (the last of which had yet to appear in Arthur's day) .

Dyce shows several figures wearing chain mail. It is unlikely that such armour was known in the time of the historical Arthur; but since chain mail is the earliest form of armour in these islands, the decision was taken to depict the Arthurian knights as wearing it. But Dyce complained bitterly about the time it took to paint it - he claimed it seriously delayed the completion of the work.

Progress was in any case painfully slow, and on the 30th of May 1854 Dyce asked to be granted 'exclusive possession' of the Robing Room. The request was passed on by the Secretary of the Fine Arts Commission to the Queen:

The Commissioners humbly pray that Her Majesty will be pleased, on the occasion of the Opening or Prorogation of Parliament, to give up the use of the Robing Room.
- Sir Charles Eastlake

The Queen consented, and for the next few years the Robing Room became, effectively, Dyce's studio - in fact he gave it as his address. But during these years he took more and more outside work, and little progress was made on these frescoes.