Bosworth: did gunpowder win the day?

This article was first published in the March 2010 issue of BBC History Magazine

To say that Bosworth is proving a rich source of lead round shot would be something of an understatement. Two decades of metal detecting at Towton – another major battle of the Wars of the Roses, fought in 1461 – has produced just two small lead munitions. Since its discovery in March 2009, Bosworth has already yielded 22.

Such abundant evidence for the use of artillery at Bosworth is undoubtedly the greatest surprise of our investigations so far – and it opens a new, archaeological chapter in the study of the use of early gunpowder weapons. Working alongside historians, we may now finally be able to determine exactly when, where and how guns came to dominate the battlefields of Europe, unleashing a destructive force which ultimately enabled the creation of empires that spanned the globe.

The Wars of the Roses (1453–1487) lie within a crucial period in the development of firearms, during which mobile artillery was first applied in large numbers to the battlefield. By 1485, English commanders clearly realised the potential of artillery in open battle and were willing to commit substantial resources to deploy these weapons on the battlefield.

At Bosworth, the scale of the initial artillery salvo seems to have influenced the way the battle was fought, encouraging Henry’s army to make a flank attack rather than face a frontal approach under heavy fire. However, these weapons were not yet a battle-winning force. In the main action it was almost certainly through archery and then hand-to-hand fighting, just as at Agincourt or Crecy, that the battle was won. Not until Pinkie (fought against Scottish forces near Edinburgh in 1547), would an English army win a decisive victory in a major battle chiefly through the use of firepower.

Most of the lead round shot discovered at Bosworth ranges in diameter from less than 30mm up to 94mm – roughly equivalent to the largest mobile field artillery piece in common use in following centuries. In contrast only two or possibly three lead bullets, likely to have been fired by ‘hand cannons’ – an early type of hand gun with a large bore – have so far been recovered from the site. But this is no surprise. With one or two notable exceptions, such as St Albans in 1461 where a company of foreign hand gunners were deployed, handheld firearms were rarely employed by English armies until the mid-16th century. The effectiveness of the English longbow meant that the introduction of the early handgun was not a priority here compared to other parts of Europe.

The later 15th and earlier 16th century was a period of great experimentation and innovation in the technology of gunpowder weapons – something confirmed by the variation in type and size of munitions fired at Bosworth. All the types reported in the documentary sources for the first half of the 16th century are present. Some are of solid lead but most are composite – several have an iron cube at their core, others a large pebble, while yet more contain either small shards or large chunks of flint. The reasons for this are now hotly debated. Was it simply to save lead? Was it an attempt to give the munitions special ballistic properties? Or was it perhaps to reduce their weight because the gun barrels, many of which were made of wrought iron rather than the cast iron or bronze typical of later centuries, simply could not take the pressures that a heavier ball would cause?

By the time of the Civil War in the 1640s, composite munitions had long since disappeared, replaced by cast iron, with only some of the smallest artillery pieces still using solid lead munitions. By then the character and battlefield role of gunpowder weapons was well-established and firepower often decided the outcome of battles.

Hand cannons

Determining how many artillery pieces were actually firing, and whether it was fire from both armies, will require more research and experimentation for there is, as yet, no comparative data from any other battlefield. For example, some of the munitions of nearly identical diameter could have been fired from a ‘ribaudequin’, an artillery piece which could have three or more barrels on a two-wheeled carriage. However, there are so many different diameters present that there must have been at least ten pieces of artillery and two hand cannons present – probably far more.

It is certain that other munitions remain to be recovered, while others may have been lost in the small areas now built up, and a few more were perhaps retrieved by ploughmen in former centuries, though no record of this has yet been found.

The importance of Bosworth is not that it is the first place where such guns were used in battle. Nor did it see their first large-scale use – the Swiss captured 400 when they defeated the Burgundian army at Grandson in 1476. Neither was it the guns that won the battle.

No, the great excitement of the discoveries at Bosworth is that it opens the door on the archaeological study of the origins of firepower. It shows that where sites have not been ravaged by treasure hunters, archaeology may reveal the numbers and sizes of guns actually used on the battlefield, where they were positioned and the intensity of fire they laid down. Complemented by firing experiments and the application of various techniques of scientific analysis, the evidence on the lead munitions may even provide clues as to the construction, range and effectiveness of the guns themselves.