Bizet's departure for a summer trip coincided with the outbreak of war between Sardinia/Piedmont, supported by France, and the Austrians. Being away from the Villa meant that the walking party of three men and a dog heard little or nothing of the news. They were confident that the war would not reach them and that Frenchmen were not regarded in towns they visited as the enemy.

The Austrians were provoked into declaring war on April 27th, allowing Napoleon III to send a large French army to Italy, half arriving by sea at the port of Genoa and half marching over the Mont St Cenis pass to Turin. The first battle of the war, at Montebello close to the border of Lombardy, took place on May 20th. Ten days later French and Sardinian troops won another victory at Palestro. The theatre of action crossed Lombardy roughly along an easterly line from west of Milan to near Verona as the Austrians were driven back. Napoleon III brought in nearly 200,000 men, while the Sardinian strength was some 70,000. Together they outnumbered the Austrians (with 220,000). One of the principal concerns of Cavour, representing Sardinia/Piedmont, and Napoleon was the fear that Prussia might be drawn in on the Austrian side, so a speedy resolution was needed. After suffering heavy casualties, by July 11th both sides were ready to sign an armistice, although Italy was by no means yet free of hostilities.

In Genoa, Florence and Rome Bizet had sought out churches and museums and recorded, in Genoa at least, the buildings and paintings he saw, but the 1859 trip, like a similar excursion in 1858, was devoted more to the outdoors: walking, bathing and climbing. While Bizet was walking or bathing Didier was sketching the Italian landscape. The third member of the party was Camille-Adrien Pâris (1834–1901), also a landscape painter, probably a friend of Didier’s, but not a Prix de Rome prize-winner. In later years both Didier and Pâris exhibited paintings sketched or begun during these weeks on the road (see Plates II, III, IVa and IVb).