Francis, forced to abandon Lombardy after the French defeat at the Battle of Bicocca in 1522 and determined to regain possession of the territory, had ordered an invasion of the region in late 1523, with an army of eighteen thousand men under the command of Guillaume Gouffier, Seigneur de Bonnivet.

The younger brother of Artus Gouffier, seigneur de Boisy, tutor of Francis I of France, Bonnivet had been brought up with Francis, and after the young king's accession had became one of the most powerful of the royal favorites.

In 1515 he was made admiral of France.

In the imperial election of 1519 he superintended the candidature of Francis, and spent vast sums of money in his efforts to secure votes, but without success.

An implacable enemy of the Constable de Bourbon, he has contributed to the downfall of the latter.

In command of the army of Navarre in 1521, he had occupied Fuenterrabia and was probably responsible for the renewal of hostilities resulting from its not being restored.

Bonnivet had succeeded Odet de Foix, Vicomte de Lautrec, in 1523, as commander of the army of Italy.

The French army advances through the Piedmont to Novara, where it is joined by a similarly sized force of Swiss mercenaries.