MacDonald's offensive On 14 April 1799, the French Directory ordered MacDonald to help the French forces in northern Italy. Accordingly, he assembled the Army of Naples and moved north, leaving southern Italy in the hands of local forces. bringing its total field force to 36,728 soldiers. The various armies involved, from France, Austria and Russia after a long series of clashes and maneuvers will end up clashing in the great and decisive battle of the War of the Second Coalition engagement occurred west of Piacenza, a city located 70 kilometres (43 mi) southeast of Milan. The Battle of Trebbia (17-20 June 1799) was fought near the Trebbia River in northern Italy between the joint Russian and Habsburg Austrian army under Alexander Suvorov and the Republican French army of Jacques MacDonald. Though the opposing armies were approximately equal in numbers, the Austro-Russians severely defeated the French, sustaining about 6,000 casualties while inflicting losses of 12,000 to 16,500 on their enemies. The War of the Second Coalition engagement occurred west of Piacenza, a city located 70 kilometres (43 mi) southeast of Milan.