Queen Elizabeth II wasn't messing around.
And wait till you hear 'em...
William, who is still a prince, of course, will now also be His Royal Highness the Duke of Cambridge, Earl of Strathearn and Baron Carrickfergus. (That last one is real, we promise!)
Kate, meanwhile, is now Her Royal Highness the Duchess of Cambridge. And she'll technically be the Princess of Wales, but will not be addressed as such.
Queen Elizabeth had been expected to give William both English and Scottish titles. According to the statement issued by the queen's press secretary, his earldom dates back to 1357, when Robert Stewart, the High Steward of Scotland, was created Earl of Strathearn, but no one has held the title since 1943.
In case the name "Carrickfergus" didn't tip you off, the barony is Irish and dates back to 1625.
Congratulations to the now veddy official-sounding couple!