The House of Este (UKˈɛsti , USˈɛsteɪ , ˈɛste) is a European dynasty of North Italian origin whose members ruled parts of Italy and Germany for many centuries.
The original House of Este's elder branch, which is known as the House of Welf, included dukes of Bavaria and of Brunswick. This branch produced Britain's Hanoverian monarchs, as well as one Emperor of Russia (Ivan VI) and one Holy Roman Emperor (Otto IV).
The original House of Este's younger branch, which is simply called the House of Este, included rulers of Ferrara (1240–1597), and of Modena (–1859) and Reggio (1288–1796). This branch's male line became extinct with the death of Ercole III in 1803.
According to Edward Gibbon, the family originated from the Roman Attii family, which migrated from Rome to Este to defend Italy against the Ostrogoths. However, there is little evidence to support this hypothesis. The names of the early members of the family indicate that a Frankish origin is much more likely. The Encyclopædia Britannica regards this family as a branch of the Obertenghi.
The first known member of the house was Margrave Adalbert of Mainz, known only as the father of Oberto I, Count palatine of Italy, who died around 975. Oberto's grandson, Albert Azzo II, Margrave of Milan (996–1097) built a castle at Este, near Padua, and named himself after the location. He had three sons from two marriages, two of whom became the ancestors of the two branches of the family:
Welf IV, the eldest (d. 1101), was the son of Kunigunde (d. 1056), the last of the Elder Welfs. He inherited the property of his maternal uncle, Welf, Duke of Carinthia, became duke of Bavaria in 1070, and is the ancestor of the elder branch, the House of Welf.
Hugh, issue of Azzo's second marriage to Garsend of Maine, inherited the French County of Maine, a legacy of his mother's dowry, but sold it one year later and died without heirs.
Fulco I, Margrave of Milan (d. about 1128/35), the third son, is the ancestor of the younger Italian line of Este.