William III (c. 970 – 1042) was the third

Marquis of Montferrat The Marquises and Dukes of Montferrat were the rulers of a territory in Piedmont south of the Po and east of Turin called Montferrat. The March of Montferrat was created by Berengar II of Italy in 950 during a redistribution of power in the ...

and Count of Vado from 991 to his death. He was the eldest son and successor of

Otto I Otto I (23 November 912 – 7 May 973), traditionally known as Otto the Great (german: Otto der Große, it, Ottone il Grande), was East Frankish king from 936 and Holy Roman Emperor from 962 until his death in 973. He was the oldest son of He ...

William I William I; ang, WillelmI (Bates ''William the Conqueror'' p. 33– 9 September 1087), usually known as William the Conqueror and sometimes William the Bastard, was the first Norman king of England, reigning from 1066 until his death in 10 ...

and II were the father and son, respectively, of Aleram, the first Marquis, but neither served as Marquis himself.

Life

William's religious policy was a continuation of Aleram's. He founded the monastery of Spigno. In 1014, he and his brother Riprando donated land to the abbey of Fruttuaria. Between his succession and 1002, he made other donations to

Acqui Terme Acqui Terme (; pms, Àich ) is a city and ''comune'' in the province of Alessandria, Piedmont, northern Italy. It is about south-southwest of Alessandria. It is one of the principal winemaking communes of the Italian DOCG wine Brachetto d'A ...

. While following in the familiar policy of ecclesiastical patronage, William abandoned Aleram's support of the Holy Roman Emperors. Instead, he intervened in the wars of the Italian communes which characterised early-eleventh-century Italy. He joined an anti-imperial alliance with Count Obert the Red, Marquis

Ulric Manfred II of Turin Ulric Manfred II ( it, Olderico Manfredi II; 975 992 – 29 October 1033 or 1034) or Manfred Ulric (') was the count of Turin and marquis of Susa in the early 11th century. He was the last male margrave from the Arduinid dynasty. Ul ...

, and Bishop

Leo of Vercelli Leo (''c''.965–1026) was a German prelate who served as the Bishop of Vercelli from 999. Born in Hildesheim, he was made an archdeacon by 998 and was appointed to the see of Vercelli as the candidate of the Emperor Otto III and Pope Sylvester II ...

. The allies soon found themselves at odds and warring on each other. Leo besieged

Santhià Santhià (; pms, Santià or ) is a ''comune'' (municipality) in the province of Vercelli in the Italian region Piedmont, located about northeast of Turin and about northwest of Vercelli. Santhià is home to a historic carnival named the ''Ca ...

, where William was then residing, and William, to avenge himself on the bishop, besieged

Vercelli Vercelli (; pms, Vërsèj ), is a city and ''comune'' of 46,552 inhabitants (January 1, 2017) in the Province of Vercelli, Piedmont, northern Italy. One of the oldest urban sites in northern Italy, it was founded, according to most historians, ...

and put it to flame. William signed a peace treaty with Ulric Manfred and married his son

Henry Henry may refer to: People *Henry (given name) * Henry (surname) * Henry Lau, Canadian singer and musician who performs under the mononym Henry Royalty * Portuguese royalty ** King-Cardinal Henry, King of Portugal ** Henry, Count of Portugal, ...

to Manfred's daughter

Adelaide Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...

. Even after all his allies had been pacified by imperial troops, William continued to resist Conrad II, but he fared poorly. Conrad destroyed his fortress in the valley of Orba. The ''Miracula sancti Bononii'' records William's wife as Waza. She prayed at the tomb of Saint Bononio, abbot of Santissimi Michele e Genuario di Lucedio. William died in 1042, probably before 29 January, when his son

cites him in an act donating land to the church in

Turin Turin ( , Piedmontese: ; it, Torino ) is a city and an important business and cultural centre in Northern Italy. It is the capital city of Piedmont and of the Metropolitan City of Turin, and was the first Italian capital from 1861 to 1865. The ...

. He succeeded by his elder son

Otto II, Marquis of Montferrat Otto II (also ''Otho'', ''Ottone'', or ''Oddone'') (c. 1015 – 20 November 1084) was the fourth Marquis of Montferrat from 1042 until his death. He was a member of the Aleramid dynasty. Life Otto was the son and successor of William III and Waz ...

Sources

*Caravale, Mario (ed). ''Dizionario Biografico degli Italiani: LX Grosso – Guglielmo da Forlì''. Rome, 2003.
Marchesi di Monferrato: Guglielmo III.
{{DEFAULTSORT:William 03 of Montferrat 970s births 1042 deaths Marquesses of Montferrat 11th-century Italian nobility Aleramici