The British Legion (Italian: Legione Britannica) was a military corps composed of English and Scottish volunteers, who in 1860 joined Giuseppe Garibaldi during the Expedition of the Thousand and fought for the unification of Italy, together with the Italian Redshirts, as part of their Southern Army against the Bourbon Army of the Kingdom of the Two Sicilies.

The Illustrated London News remarks that, including volunteers already with Garibaldi, the total amount is a considerable more than 1,000 volunteers in the Garibaldian Army, often from middle-class or well-paid jobs, who left their country attracted by adventure and love of freedom, to fight for the liberty of a foreign country.

Before their departure from England other British volunteers were already at the side of Garibaldi in the south of Italy, such as Hugh Forbes, who was with Garibaldi in 1849, taking part in the defence of the Roman Republic against the French troops supporting the papacy,[5] John Whitehead Peard, and the Colonel John Dunne and his "English battalion" of soldiers who were all Sicilians and called Dunne "Milordo".

After having sailed from Great Britain by the ships Melazzo and Emperor, the British Legion landed in Naples on 15 October 1860 and took part in a fight, under the command of John Whitehead Peard in Sant'Angelo up to the wall of Capua, where two volunteers were killed and eight wounded.

The Legion had a short war experience, after having advanced northwards with Garibaldi and a few regiments of Italians, on the morning of October 26, while they were in Vajrano, an Englishman from the Garibaldian outposts heard the war-cry Viva il re!, "Long live the king!