Having obtained these two objects of ambition, he now played for a dukedom. This ambition, suspected presumably in Cobham, had been the subject of epigram so early as 1742.[101] It was avowed, according to Walpole, in 1767, and, indeed, no other explanation seems adapted to his various proceedings at critical junctures. Thus, when in June 1765, George III. and his uncle Cumberland tried to form a Pitt ministry, but found that an absolute condition of such a ministry was that Temple should be First Lord of the Treasury, Temple refused on various flimsy pretexts. When these were surmounted, he declared that 'he had tender and delicate reasons' which he did not explain to the King, or, apparently, to Pitt.[102] That this unwonted delicacy and tenderness were concentrated on the superior coronet appears from the negotiation carried on by Horace Walpole in 1767, when Lord Hertford assured him of the fact that Lord Temple's ambition was now a dukedom.[103] It is not doubtful that this had now become the central preoccupation of his life, and the hereditary object of the family combination. At first sight it would seem improbable that Pitt was aware of it, for the simple reason that he would probably have made efforts to obtain it from the King. On the other hand, it is unlikely that Temple, in the affair of the Garter, having found the inestimable value of Pitt's pressure on George II., could have foregone the effort to exercise it on George III. On the whole, the most plausible conjecture appears to be that Pitt was unsuccessfully sounded by his brother-in-law. All that we know is, that when Pitt finally determined to undertake the ministry without Temple, they had a heated interview, which seems to have left deep marks on Pitt's nerves and health, but whether it turned on Temple's particular ambition or not can now only be matter for surmise.