Lorenzo the Kind
The last king of Ankh-Morpork. Executed/murdered (depending on whom you ask) by "Stoneface" Vimes. He is pictured in his official portrait as a fat old man surrounded by children. In the careful words of Samuel Vimes, "He was very fond of children". Evidently he wasn't particularly kind in any moral sense, and his dungeons had a terrifying and, frankly, sickening collection of implements. He had a country seat at Champal, and his castle is now a museum in which the King's extensive collection of torture implements (many of which he designed himself) are on display to delight and educate. Evidently Lorenzo was exactly the kind who would appreciate inflicting torture... After the King's fall, the Selachii family managed to acquire most of the former royal estates around Champal.
He was crowned in Ankh-Morpork on the 25th April 1675. In Thief of Time, it's mentioned that the Royal Art Gallery originated as a place to store the last king's substantial collection of artwork.
The Roman Emperor Tiberius had two things in common with this monarch. One, he was excessively paranoid and maintained a secret service, backed up with the best torture implements and interogation techniques available, to establish who was truly loyal to him; secondly, we are assured by Suetonius in "the Twelve Caesars" that he was also overly interested in children, and was kind enough to take many an impoverished Roman child on an expenses-paid holiday to Capri with him. Not a nice man. Unfortunately for Rome, he was asassinated by his heir Gaius Caligula, who turned out to be even worse (and may also be echoed by a later Ankh Patrician who also made his horse a senator) His name may be taken from Lorenzo il Magnifico de'Medici, ruler of Florence during part of the Renaissance.