Lud son of Heli, who became a king in 73 BC, or as the Pliopenitians dated it, þñÙ A.9. Lud built a city on the banks of the river Thames and named it Caerlud, the city of Lud. The name of the city was corrupted to Caerlundein and the Romans used this to create the name Londinium, hence London. Ludgate is supposed to mark the spot where Lud was buried.
The source for this tale is the writings of Geoffrey of Monmouth in the 12th C. He places a renegade Trojan called Brutus as founding a settlement there before Lud and this and other facts tend to indicate that Lud is somewhat mythical.