Sésia was the name of a département of the First French Empire

First French Empire

The First French Empire , also known as the Greater French Empire or Napoleonic Empire, was the empire of Napoleon I of France...

. Situated in present-day Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, it was named after the Sesia

Sesia River

The Sesia is a river in north-western Italy, tributary to the Po. Its sources are the glaciers of Monte Rosa at the border with Switzerland. It flows through the Alpine valley Valsesia and the towns Varallo Sesia, Quarona, Borgosesia and Vercelli...

 river. Its capital was at Vercelli

Vercelli

Vercelli is a city and comune of about 47,000 inhabitants in the Province of Vercelli, Piedmont, northern Italy. One of the oldest urban sites in northern Italy, it was founded, according to most historians, around the year 600 BC.The city is situated on the river Sesia in the plain of the river...

.

The département was formed on September 11, 1802, when Napoleon Bonaparte occupied the Kingdom of Sardinia

Kingdom of Sardinia

The Kingdom of Sardinia consisted of the island of Sardinia first as a part of the Crown of Aragon and subsequently the Spanish Empire , and second as a part of the composite state of the House of Savoy . Its capital was originally Cagliari, in the south of the island, and later Turin, on the...

. It was divided into the arrondissement

Arrondissement

Arrondissement is any of various administrative divisions of France, certain other Francophone countries, and the Netherlands.-France:The 101 French departments are divided into 342 arrondissements, which may be translated into English as districts. The capital of an arrondissement is called a...

s of Vercelli, Biella

Biella

Biella is a town and comune in the northern Italian region of Piemonte, the capital of the province of the same name, with some 45,800 inhabitants as of 2009. It is located about 80 km northeast of Turin and about 80 km west-northwest of Milan.It lies in the foothills of the Alps,...

 and Santhià

Santhià

Santhià is a comune in the province of Vercelli in the Italian region Piedmont, located about 50 km northeast of Turin and about 20 km northwest of Vercelli....

. It was disbanded after the defeat of Napoleon in 1814.

Its territory is today divided between the Italian provinces of Vercelli and Biella.