8.3 — Gunpowder and the Military Revolution

A medieval castle is a tall thin stone wall. Its whole design assumes that the attacker's problem is getting over it or through it with muscle power, so it should be as high as possible and it should be built where the ground makes approach difficult.

A cannon ball does not care how high a wall is. It cares how thick it is at the point of impact, and a tall thin wall is the easiest possible target — the higher it is, the more its own weight works against it once the base is breached.

Between about 1450 and 1520 every fortification in Europe became obsolete. The French artillery train reduced English strongholds in Normandy in weeks in the 1440s; when Charles VIII invaded Italy in 1494 with a train of mobile bronze cannon, Italian fortresses that had held out for months previously fell in days.

And then people built something else, and what they built changed the state itself. That chain is this chapter.

Gunpowder

Discovered in China by alchemists looking for an elixir of immortality (Chapter 7.9), and in military use there from the tenth century.

The chemistry. Saltpetre (potassium nitrate), charcoal and sulphur. The saltpetre is the essential part: it is an oxidiser, meaning it supplies the oxygen for combustion internally, so the mixture burns without needing air from outside. That is why it works in a sealed tube, and it is why the expansion is fast enough to be explosive rather than merely a fire.

Roughly 75 percent saltpetre, 15 percent charcoal, 10 percent sulphur became the standard proportion after centuries of empirical adjustment.

Saltpetre was the bottleneck for centuries. It was extracted from the nitrogen-rich soil of stables, dovecotes and latrines by leaching and crystallising. "Saltpetre men" in England had legal authority to dig up other people's floors and cellars, which was as unpopular as it sounds. India was the world's major source of good natural saltpetre, which is one of the underappreciated reasons Bengal mattered so much to the European trading companies (Chapter 6.16).

And corning solved a problem. Loose powder separates in transport, the components settling by density, and burns unevenly. Wetting the mixture, forming it into cakes and breaking it into grains keeps the proportions locked together in each grain and gives a faster, more predictable burn. Corned powder from the fifteenth century is substantially more powerful than the earlier serpentine kind.

The gun

Early cannon were forged from iron staves hooped like a barrel — hence the word barrel — and they burst frequently. James II of Scotland was killed in 1460 by one of his own exploding guns.

Casting in bronze, using the bell-founder's technique, produced far more reliable pieces. Bronze is expensive; cast iron guns, developed in England from the 1540s, were cheaper and heavier and made naval armament affordable in quantity.

Handguns evolved through three lock mechanisms and each is a step in reliability. The matchlock applies a burning cord to the touchhole — cheap, and useless in rain and visible at night. The wheellock strikes sparks from pyrite with a spring-driven serrated wheel — expensive, and it works concealed, which is why it was associated with assassination and was banned in several places. The flintlock, from the seventeenth century, strikes flint on steel and is cheap, reliable and quick.

And the socket bayonet, from the 1680s, is the decisive infantry development (Chapter 6.15): it fits around the barrel rather than plugging it, so the musket can fire with the bayonet fixed. One soldier now performs both the musketeer's and the pikeman's role, and pikes disappear from European armies within a generation.

The star fort

The answer to cannon was worked out in Italy and is called the trace italienne.

Low, thick and angled. Walls were built low so they presented a small target, and enormously thick — often earth-filled behind a masonry face, because earth absorbs a cannon ball where stone shatters.

And the shape is the clever part. Angled projecting bastions, arrow-headed in plan, placed so that the face of every wall could be swept by fire from the flank of the neighbouring bastion. A medieval round tower has ground at its base that cannot be covered by anyone; a properly designed bastioned trace has no dead ground anywhere. An attacker approaching any wall is being shot at from two directions along the wall's own face.

The consequences are the point of this chapter.

Sieges became long again, so the artillery advantage was cancelled — but at a cost.

Fortresses became enormously expensive. A bastioned trace around a city required earthworks and masonry on a scale that could consume years of a state's revenue.

And armies became enormous, because taking such a fortress required surrounding it completely, which requires many more men than storming a wall. Army sizes in western Europe rose by roughly a factor of ten between 1500 and 1700 — Spain's forces went from tens of thousands to over a hundred thousand, and France's peacetime army under Louis XIV exceeded 150,000 with wartime peaks far above.

The fiscal-military state

This is the mechanism by which gunpowder produced the modern state, and it is one of the most important causal chains in this volume.

Bigger armies, expensive fortresses and expensive artillery cost money on a scale no medieval ruler had ever raised.

So states had to develop the capacity to extract it. That meant: permanent taxation rather than occasional feudal aids; a bureaucracy to assess and collect it; records — surveys, censuses, registers; public debt, so that the cost of a war could be spread over decades (Chapter 9.2); and a body that could authorise new taxes, which in several countries meant a parliament with real leverage.

States that could do this survived. States that could not were absorbed. The number of independent political units in Europe fell from many hundreds in 1500 to a few dozen by 1800, and the sorting criterion was fiscal capacity.

The historian Charles Tilly's formulation is the standard one: war made the state, and the state made war. The modern state — with its tax office, its statistics, its standing army and its national debt — is substantially a machine built to pay for gunpowder.

And it produced representative government as a by-product in some places. A ruler who needs consent to tax has to give something in exchange. England's parliament gained its power through repeated fiscal crises, and Chapter 10.1 traces exactly that. Rulers who could fund themselves without consent — from silver mines, or later from oil (Chapter 1.12) — did not have to bargain, and Chapter 13.1 makes that the general rule.

Ships and guns

The other transformation is at sea and it decided the shape of the next four centuries.

The critical development is the gunport — a hatch cut in the hull, closed by a hinged lid when not in use — which allowed heavy guns to be mounted low in the ship where their weight does not destabilise it. Attributed to a French shipwright around 1500.

Combined with the full-rigged ship — square sails for driving power, lateen sails for pointing closer to the wind, and a stern-post rudder — the result is a vessel that can cross oceans and carry a battery of heavy artillery.

This is a genuinely new object in world history. No other civilisation had built anything like it, and its capabilities are specific: it can appear anywhere on a coast, out-range and out-shoot anything ashore in the immediate vicinity, and leave.

The Portuguese demonstrated it in the Indian Ocean from 1500 (Chapter 8.4). At Diu in 1509 a Portuguese fleet defeated a combined Gujarati, Mamluk and Ottoman force, and thereafter Portugal issued passes — cartazes — that ships trading in the Indian Ocean were required to buy. A trading system that had run for a thousand years on the monsoon and on merchant custom was taxed at gunpoint by a small European kingdom with about a million people.

The reason no Indian Ocean power answered it is Chapter 6.1's point: those states were land powers whose navies were coastal, and building an ocean-going gun platform requires a shipbuilding tradition, a gun-founding industry and a state that considers sea control its business.

What this does not explain

Two cautions, because the "gunpowder made Europe dominant" story is frequently overstated.

Other powers adopted gunpowder fully and used it well. The Ottomans took Constantinople with the largest artillery in the world (Chapter 7.3), and the "gunpowder empires" — Ottoman, Safavid and Mughal — are named for their effective use of it (Chapter 8.10). Babur won Panipat with artillery in 1526 (Chapter 6.11).

The gap opened in the eighteenth century and it was organisational. Chapter 6.15 made this argument in detail: drill, standardised equipment, sustained finance and unified command, rather than access to the weapons.

So the honest statement is: gunpowder transformed warfare everywhere it went, and it transformed the state most thoroughly in Europe, because Europe's political fragmentation meant constant war between roughly matched competitors, and constant war between roughly matched competitors is the condition that forces fiscal and administrative development. A single large empire with no peer competitor — Ming China, Mughal India — faced no such pressure.

This is Chapter 16.3's argument in its military form: competition between comparable units drives capability, and the absence of it permits stagnation. It is also a grim argument, since the mechanism is war.

Where this shows up in your life

The income tax, the census, the national debt, the professional civil service and the standing army all trace substantially to the need to pay for this.

Star-fort geometry is visible from the air at Palmanova in Italy, Naarden in the Netherlands, and in the plan of several colonial-era Indian and American forts — the outline of Vauban's fortifications shows in the street plans of dozens of French towns.

And the phrase "keep your powder dry" is from the matchlock era and means exactly what it says.

What the next page covers

Armed ocean-going ships existed. Chapter 8.4 asks why Europe used them to sail into the Atlantic — what Europeans were actually looking for, what the navigational and financial problems were and how each was solved, why Portugal and Spain went first, what Vasco da Gama found when he reached India and what he did about it, and why the alternative — a Chinese fleet reaching Europe — did not happen even though the ships existed sixty years earlier.