London in 1666 was a fire waiting to happen. The medieval city was densely packed with timber-framed buildings, many with thatched roofs, crammed so closely that upper stories nearly touched across narrow lanes. A hot, dry summer had left the city parched. Warehouses along the Thames held flammable goods - pitch, tar, oil, hemp, coal, timber.

Firefighting was primitive. There was no fire brigade. The main technique was pulling down buildings to create firebreaks, using hooks attached to long poles. But this required the Lord Mayor's permission to destroy property, and the Lord Mayor was asleep, unimpressed by this particular fire.

By morning, the fire had spread along Pudding Lane toward the Thames. The strong east wind drove it westward through the warehouses. Flames leapt from building to building. The fire created its own weather, generating winds that spread it faster than firefighters could respond.

Samuel Pepys, the famous diarist, watched from the Tower of London as the fire advanced. He rushed to Whitehall to warn King Charles II, who ordered houses demolished to create firebreaks. But the order came too late, and property owners resisted losing their buildings. The fire jumped every gap.

Old St. Paul's Cathedral, the medieval building that had dominated London's skyline for centuries, became a target for flying embers. The scaffolding from ongoing repairs caught fire. Lead from the roof melted and ran down the streets. The enormous building became an inferno, its destruction visible for miles.

Books and papers from nearby printers and booksellers had been stored in St. Paul's crypt for safety. They burned with everything else. The destruction of the cathedral symbolized the fire's totality - even the most sacred and solid structures could not withstand it.

The fire finally died on September 5, partly because the wind dropped and partly because organized firebreaks finally worked. King Charles II personally directed firefighting efforts, working alongside common laborers. Gunpowder was used to blow up houses in the fire's path, creating gaps too wide to jump.

The destruction was staggering: 373 acres within the city walls, 63 acres outside, 13,200 houses, 87 churches, and most of the city's public buildings. Yet official death counts recorded only six people - almost certainly a dramatic undercount. Many bodies would have been cremated beyond recognition, and the deaths of the poor went unrecorded.

The fire created an opportunity to rebuild London according to modern principles. Christopher Wren proposed a rational grid of wide streets and open squares. John Evelyn submitted his own plan. Neither was adopted - property rights were too entrenched, and the need for housing too urgent.

But London changed nonetheless. Stone and brick replaced timber. Streets were widened. Wren rebuilt 51 churches, culminating in the new St. Paul's Cathedral that still dominates the skyline. The Monument, a column 202 feet tall standing 202 feet from the bakery on Pudding Lane, commemorates the fire and the city's rebirth. London burned medieval and rose modern.