LitCharts assigns a color and icon to each theme in The Once and Future King, which you can use to track the themes throughout the work.
Chivalry, Satire & Medieval Life
Fate (Time)
Quest and The Holy Grail
Might vs. Right
War
Summary
Analysis
Months later, Gawaine and Mordred sit in the justice room. They are both dressed in black—the uniform of Mordred's gathering political party. There are now thousands of his supporters, all over the country, sharing his convoluted nationalism. They are talking about the unfairness of the pope's forgiveness and about the pageant taking place to grant forgiveness to Lancelot and Guenever.
Although the problem of the lovers seems to have been resolved for Arthur, there is a gathering threat White alludes to: Mordred's growing political party. He has taken Agravaine's advice to heart and begun to forge a nationalistic movement to help him usurp the King.
Active
Themes
The pageant reaches the justice room. The king, tired and somber, enters at the end of the processions. Finally, Lancelot and Guenever enter at their cue: they are dressed in white cloth and the Queen carries an olive branch. She looks ungraceful, now that she is no longer young or lovely. The ceremony to forgive the two proceeds, but Gawaine and Mordred refuse to accept their apologies. Finally, the King grants Guenever forgiveness and Lancelot exile to France.
This whole decadent pageant for forgiveness appears both contrived and darkly comedic: both Lancelot and Guenever look ridiculous in their outfits, while Arthur's official forgiveness of them is marred by Mordred's snide comments about their guilt.
Active
Themes
Lancelot has fifteen days to leave the kingdom. He walks all the way to Dover, from where he will depart. He walks unclothed, unshod and carrying a cross. He will walk steadily, without haste, all the while Gawaine and his men skulk at his heels, waiting for revenge.
In his penance, Lancelot re-assumes his stately, pious figure that was taken away from him with the farcical pageant. Gawaine, meanwhile, has given in to his brutal nature. His brother's deaths have pushed him into a blind desire for revenge (not that different than Lancelot's blind love for Guenever).