The formal history of the march began around 951 after Berengar of Ivrea became the king of Italy. At that time Berengar completed the reorganization of the military districts south of the Po River that was begun by his predecessor
Hugh of Arles to defend against attacks by the Saracens from the sea. In doing so, he formed three new territories, for which he appointed margraves with loyal followers: • Marquisate of Turin, which came to be known for a short period as Marca Arduinica based upon Berengar’s appointment of
Arduin Glaber as the margrave. Prior to his appointment, Arduin Glaber had been invested as count of Turin in 941 by Hugh of Arles. To his credit, Arduin had captured Turin and the Susa Valley from the Saracens. • Western Liguria, which came to be known for a short period as Marca Aleramica based upon Berengar’s appointment of his son-in-law,
Aleramo as the margrave. • Eastern Liguria, which came to be known for a short period as Marca Obertenga based upon Berengar’s appointment of
Oberto von Luni as the margrave. This territory was also known as the marca Januensis or March of Genoa as its capital city was Genoa. In 961, Holy Roman Emperor
Otto I invaded Italy and displaced Berengar. Otto then continued the work that had been done to reorganize the northwest into the three great marches and in 964 he appointed Arduin margrave of Turin. The march continued to be ruled by members of the Arduinici thereafter. Arduin Glaber's son
Manfred I succeeded him and his son,
Ulric Manfred II, succeeded him. Ulric had no son, so he left the march to his daughter
Adelaide. Although Adelaide ruled in her own right, de jure control passed to her husband
Otto,
count of Aosta. Their descendants would later comprise the
House of Savoy. Gundulph, the father of
St Anselm, may have represented a collateral branch of Manfred's dynasty. After Adelaide’s death in 1091, the march of Turin broke up. Comital authority in the city of Turin was invested in the
bishop of Turin (1092) and the city itself became a
commune (1091). In 1092, the
emperor Henry IV appointed his son
Conrad as margrave of Turin (Conrad was Adelaide’s grandson via her daughter
Bertha of Savoy). Although Conrad attempted to gain control of the march, his power was never effectual and the title was largely nominal. Instead, the northern part of the march of Turin was absorbed into
Savoy, which was ruled by another of Adelaide’s grandsons,
Humbert II (many centuries later, Turin became the capital of this dynasty.) To the south, lands which had composed the march of Turin were annexed by Adelaide's nephew,
Boniface del Vasto. ==List of Margraves of Turin==