The "House at the Back", the largest of the three houses which were combined to make Number 10, was a mansion built in about 1530 next to Whitehall Palace.
"Tagumine maja", suurim kolmest hoonest, mis kõik hiljem omavahel üheks majaks nr 10 ühendati, oli umbes 1530. aastal Whitehalli palee kõrvale ehitatud aadlielamu.