As London settled in to sleep on May 31, 1915, a monstrous airborne machine blotted out the stars of the British night. Using the glow of the River Thames as a guide, the biggest flying vessel ever constructed droned over the city. As a trap door opened from underneath the futuristic 650-foot-long craft, German troops sent 90 incendiary bombs and 30 grenades plummeting from the dark menace. London rattled. Explosions illuminated the night. Panic tore through the city.

The attack seemed to be ripped straight out of a science-fiction novel. Eight years before, in fact, H.G. Wells had written “The War in the Air,” a novel in which Germany dispatched “a huge herd of airships,” some as mammoth as 2,000 feet long, in a surprise bombing raid against New York City. For Londoners, however, the storyline was all too real as dawn arrived with seven dead and 35 wounded.

The carnage that had infested the Western Front hundreds of miles away across the English Channel had now arrived at the British capital. For the first time in history, London was under attack from the air, and the craft delivering the bombs was a terrifying new weapon of mass destruction—the zeppelin. The colossal hydrogen-filled ocean liners of the air—named for German army officer Count Ferdinand Graf von Zeppelin who developed them in 1900, three years before the Wright Brothers took flight—that for years had carried civilians on pleasure cruises were now deployed to kill them.

In the early months of World War I, the German military employed their airships, which were capable of traveling 85 miles per hour and hauling two tons of explosives, on bombing raids on the cities of Liege, Antwerp and Paris. On January 19, 1915, the zeppelins struck Great Britain for the first time, dropping bombs on the seaside towns of Great Yarmouth and King’s Lynn. With the targeting of civilian populations from the air, modern warfare had arrived.

“Nowadays there is no such animal as a non-combatant,” justified German zeppelin corps commander Peter Strasser, “modern warfare is total warfare.”

Germany hoped that the bombing of Britain would spark such fear that it would force the country out of the war. The military ramped up zeppelin production to the point that Germany ceased production of sausage because the intestinal linings of cows that were used as sausage skins were required to fashion the skins of the zeppelins’ leak-proof hydrogen chambers. (A quarter-million cows were needed to build one zeppelin.)

After the initial strike on London in May 1915, zeppelins continued to hit the city with impunity, timing raids to coincide with good weather and moonless nights. Not wanting to foment panic, British civil authorities gave few air raid warnings beyond policemen on bicycles blowing whistles and shouting for people to “take cover.”

Technology also limited what Britain could do to stop the zeppelins early in the war because its airplanes were unable to soar as high as the lighter-than-air craft and machine gun fire had no effect. Londoners huddled in basements and descended deep underground in the city’s Tube stations to escape the terror from the skies.

On September 8, 1915, the shadow of a sleek cigar-shaped zeppelin passed over the dome of St. Paul’s Cathedral and unloaded a three-ton bomb, the largest ever dropped at the time, on the city’s financial hub. The attack caused massive damage and killed 22 civilians, including six children. The zeppelin raid would be the worst of the war on London.

The public now demanded more protection from the airships they now referred to as “baby killers.” Britain instituted blackouts and installed massive searchlights. Anti-aircraft defenses were diverted from the front lines in France and positioned around the capital. Authorities drained the lake in St. James’s Park to prevent its nighttime glitter from directing zeppelins to nearby Buckingham Palace, and to build morale, Charlie Chaplin filmed a propaganda short in which he brought down a zeppelin.

The British also began to target the zeppelins’ major vulnerability, their highly flammable hydrogen. By mid-1916, they had developed airplanes that could reach higher altitudes and fire both explosive bullets, which could tear large holes into a zeppelin’s outer skin and allow oxygen to pour into the hydrogen chambers, and incendiary bullets, which could light the volatile gaseous cocktail on fire.

The new defenses were in place on September 2, 1916, when the Germans launched their largest raid of the war with a fleet of 16 airships heading to London. The searchlights scouring the skies caught one of the silver zeppelins sparkling in their beams, and Royal Flying Corps pilot William Leefe Robinson soared over 11,000 feet and closed in upon his prey. He raked the zeppelin with bullets that punctured the leviathan like harpoons. Suddenly, the mighty airship ignited like a torch, and the fireball fell from the sky like a shooting star that could be seen for 100 miles around. Londoners cheered and sang patriotic tunes as the incinerated zeppelin plummeted to earth.

The tide had been turned. Other British pilots achieved similar successes in shooting down airships. Strasser ordered his fleet to fly at higher altitudes, but crews began to suffer from the frigid temperatures and became incapacitated from oxygen deprivation. The zeppelin raids on London continued, but far less frequently, and by 1917 Germany began to deploy heavy biplane bombers in their stead. Over the course of the war, German zeppelins staged more than 50 attacks on Britain, but at a heavy price with 77 of their 115 craft either shot down or disabled.

The German zeppelin raids on London killed nearly 700 and seriously injured almost 2,000, but the casualties did not include the ultimate German aim of breaking British morale. The waging of total war against civilian populations, however, did not fade with the Zeppelin era. Two decades later, terror again fell from London’s skies when the next world war arrived, this time with much deadlier consequences as nearly 20,000 of the city’s residents died in the London Blitz.