When Naples declared war on Austria, Austrian troops were still gathering in Lombardy. Only a small force of about 6,600 men commanded by General Bianchi, who was stationed in the
Duchy of Modena
, were in position to check the Neapolitan advance. Murat with his main army of around 40,000 men had already established a main headquarters in
Ancona
and were marching north. Following a minor skirmish on 30 March near
Cesena
, the Austrians under Bianchi fell back to a new defensive line behind the Panaro River. This allowed the Neapolitans to capture
Bologna
on 2 April, from where they prepared another assault on the Austrians.
On 3 April, one day after capturing Bologna, a Neapolitan division under the command of
Michele Carrascosa
attempted to cross the Panaro. After being driven back from two other bridges, the Neapolitans finally crossed the Panaro at
Castelfranco Emilia
and made a sweeping charge on Bianchi's position. As heavy fighting continued in the center of the Austrian position, Murat ordered a column under General
Colletta
to sweep left and push on the Austrian fight flank. Outnumbered, the Austrian right flank was turned and Bianchi was compelled to sound the retreat. With more Neapolitan troops arriving from Bologna, the Austrian retreated back to their lands behind the Po River. Following the battle, Carascosa and his troops immediately occupied the major towns of the
Duchy of Modena
:
Modena
,
Reggio Emilia
and
Carpi
.