There is an interesting letter from George III to Lord Bute, 28 April 1763, in which he discusses the efforts of the Earl of Egremont to obtain a Marquessate, which was refused (and at any rate the earl died later that year). The king said that he regretted making John Spencer a Viscount and Talbot an Earl.
Egremont felt that he should be rewarded for his part in securing the recent Peace with France and Spain.
"G. Greenville [recte Grenville] was with me this morning... he told me Lord Egrem is very sour, that his illhumour broke out after dinner yesterday, on this he open’d to me the affair of the Marquisate ; I answered that my dear friend had pressed me very much to do that thing ; but that
I had long very long resolved to make [no] Marquises, that I repented having put Lord Talbot and Lord Spencer, the former over so many Viscounts and Barons the other over the Barons ; that I look’d on our Peerage as the most honourable of any country, and that I never would hurt them by putting the juniors of them over the seniors that I intended Lord Egre. the garter whenever I gave one to Lord Halifax; G. Greenville in his tiresome manner dwelt on his having been the pen employ’d in the Peace, but finding he gained no ground, desisted ; Lord Hal. told me the same story: said he never saw a man so illhumoured as Lord Egre. seemed yesterday : I saw his speaking was par maniere d’acquit, and that he manifestly seem’d pleased that he gain’d no ground, so that I suppose I shall tomorrow see this very angry Lord: I am totaly indifferent whether he means to continue so ; perhaps indeed his quitting my service is the best part he can take ; for if he goes unpleasantly my affairs would suffer by it. "
page 326 at:
file:///C:/Users/dpthe/Desktop/george%20iii%20bute.pdf