The Lomellina (Western Lombard: Ümlína/Lümelína) is a geographical and historical area in the Pianura Padana (Po River's valley) of northern Italy, located in south-western Lombardy between the Sesia, Po and Ticino rivers.
It includes some 60 comuni (municipalities), the most important today being Vigevano and Mortara; the name however derives from its ancient capital Lomello. The area is particularly renowned for its rice paddies: the crop has been cultivated here since the sixteenth century.
In ancient times Lomellina was inhabited by the Ligurian tribes of the Laevi, and the Marici (co-founders of Ticinum, the modern Pavia) and the Libici (founders of Vercelli). Later they were Romanized. Although crossed by an important road connecting Ticinum to Augusta Taurinorum (the modern Turin), the region seems not to have been intensively urbanized under the Romans, with the exception of the area of Vigevano.
With the fall of the Western Roman Empire and the arrival of the Lombards, who set their capital in Pavia, Lomellina acquired importance, with a comital dynasty Conti di Lomello assigned to the House of Candia rising in Lomello. The city of Pavia conquered Lomello in 1146, and the area was later under the Visconti, as part of the Duchy of Milan.
In 1707, after the War of Spanish Succession, a part of Lomellina was conquered by the Piedmontese House of Savoy and made an autonomous province. The area of Vigevano and Robbio, called Contado di Vigevano and which had been autonomous since 1532, was also acquired by Piedmont in 1743.