This category lists people who held the title King of Italy in one Harry Turtledove timeline or another, or in OTL, or both. Some also ruled one or more of the states on the Italian peninsula that eventually became part of the unified nation-state of Italy in the 19th Century.
Prior to the unification of the modern Kingdom of Italy in the 19th Century, the Italian Peninsula was dominated by the Roman Empire for several centuries. After the Western Empire's collapse, Italy was ruled by Roman military leader Odacer, the first person to hold the title of "King of Italy". Taking the throne in 476 CE, he was overthrown by the Ostrogoths in 493, who established a dynasty that ruled until the Byzantine Empire retook Italy in 553. The Lombards entered the peninsula in 568, and over the course of the next centuries, were able to establish a state that incorporate nearly all of Italy. When Charlemagne defeated the Lombards in 774, he took the title "king of the Lombards" for himself. Upon the death of Charles III the Fat in 887, Italy fell into a period called the Feudal Anarchy, which saw numerous would-be monarchs carving out new kingdoms in Italy. In 962, after successfully invading Italy, the Holy Roman Emperor Otto I added the title "King of Italy" to his many other titles. Holy Roman Emperors used that title until Charles V. Adding to the confusion, throughout this period, a number of smaller states rose to prominence on the Italian Peninsula that were not considered part of the "kingdom" of Italy. Thus, along with being the King of Italy, several emperors and their heirs were also, for example, the King of Sicily, or the Duke of Milan. Many of these offices continued on after Charles let the title king of Italy go defunct.
In 1805, Napoleon was crowned King of Italy, and maintained the title until 1814. The next monarch didn't into being until 1861 under the House of Savoy, which extended its rule over the entirety of the Italian Peninsula, and even carved out a colonial empire and saw a period of economic growth. The monarchy remained in place through the First and Second World Wars. The monarchy's decision to allow the Fascist dictatorship of Benito Mussolini and Italy's entry into the Second World War on the side of the Axis was a disaster for the country. In 1946, a constitutional referendum ended the monarchy and established the Italian Republic. The king was replaced as head of state by a president.
In most of the works of Harry Turtledove, the King of Italy has played a minor role. Indeed, the only two people who appeared specifically as "King of Italy" in Turtledove's works are the historical Victor Emmanuel III of Italy and the fictional Umberto III of Italy.