Battle of Cannae Hannibal at Cannae, with approximately 86,000 Roman and allied troops. They massed their heavy infantry in a deeper formation than usual, while Hannibal used the double-envelopment tactic and surrounded his enemy, trapping the majority of the Roman army, who were then slaughtered. The loss of life on the Roman side was one of the most lethal single day's fighting in history; Adrian Goldsworthy equates the death toll at Cannae to "the massed slaughter of the British Army on the first day of the Somme offensive in 1916." Only about 15,000 Romans, most of whom were from the garrisons of the
Battle of Cannae intercalations, either by accident or for political advantage. A review of the evidence led P.S. Derow to identify the equivalent Julian date would be 1 July 216 BC; other authorities have suggested other Julian dates. Figures for troops involved in ancient battles are often unreliable, and Cannae is no exception. They should be treated with caution, especially those for the Carthaginian side. The Carthaginian army was a combination of warriors from numerous regions, and may have numbered between 40,000-50,000. Along with the core of an estimated 8,000 Libyans, there were 8,000 Iberians, 16,000 Gauls (8,000 were left at camp the