Edward St John de Nobbes
Motto: CAPITE OMNIA
To Capture All
Edward St John de Nobbes was the last Earl of Ankh, who lived some 80-100 years before the "present day". His family has been nobility for many generations and could trace their line all the way back to a cousin of the last king of Ankh-Morpork. Despite dalliances with chambermaids and other members of the lower orders, he "died without issue", and the line died out.
However, one of those dalliances with a "parlourmaid of unknown lineage" had the inconvenient long-term result of Slope Nobbs...
There was also the issue that an Earl is the highest rank of nobility save for that of duke (Which Ankh-Morpork did not have either). So should the line to be resurected then any Earl of Anhk would have a claim to the Golden Throne of Ankh...