William IV (c. 1030 – 1100) was the fifth

Marquis of Montferrat The marquises and dukes of Montferrat were the rulers of a territory in Piedmont south of the Po River, Po and east of Turin. The March of Montferrat was created by Berengar II of Italy in 950 during a redistribution of power in the northwest o ...

from 1084. The date of William's birth is unknown, but it most likely took place between 1030 and 1035. He was the eldest son of Otto II and Constance of Savoy.

Life

He first appears in a document of 1059, when he is placed in power over the city of

Savona Savona (; ) is a seaport and (municipality) in the west part of the northern Italian region of Liguria, and the capital of the Province of Savona. Facing the Ligurian Sea, Savona is the main center of the Riviera di Ponente (the western se ...

, probably as per a request of the citizenry for a ruler of their own. He was present when the

Emperor Henry IV Henry IV (; 11 November 1050 – 7 August 1106) was Holy Roman Emperor from 1084 to 1105, King of Germany from 1054 to 1105, King of Italy and Burgundy from 1056 to 1105, and Duke of Bavaria from 1052 to 1054. He was the son of Henry III, Holy ...

donated the monastery of Breme to the church of

Pavia Pavia ( , ; ; ; ; ) is a town and comune of south-western Lombardy, in Northern Italy, south of Milan on the lower Ticino (river), Ticino near its confluence with the Po (river), Po. It has a population of c. 73,086. The city was a major polit ...

. In an act dated 15 September 1096, Uvilielmus, the son of the late Uviliel and Ota, the daughter of the late Tebald, and Uvilielmus, the son of the aforementioned Uviliel and Ote, and Oto, the son of Oton, or Peter, the son of Robert, and his spouse Ermengarda, the daughter of the aforesaid Tebald and Tezo, the son of the aforesaid Petri and Ermengarde conceded their rights over the church of Santo Stefano di Allein. By his second marriage with Otta di Aglié, William was the father of his successor Rainier. He had two children by his first marriage, but their fate is unknown.

Sources

*Caravale, Mario (ed). ''Dizionario Biografico degli Italiani: LX Grosso – Guglielmo da Forlì''. Rome, 2003.
Marchesi di Monferrato: Guglielmo IV.
{{DEFAULTSORT:William 04 of Montferrat 1030s births 1100 deaths Marquesses of Montferrat 11th-century Italian nobility Aleramici Year of birth uncertain