The world's 'deadliest day' when over 800,000 people died - not because of a war

Shaanxi, China, where the appalling natural disaster occurred. (Image: Getty)

A catastrophic event some 500 years ago is believed to have been the most deadly day in human history - but it wasn't caused by war.

On January 23 1556, Shaanxi, a province in northwestern China, was struck by a major earthquake, estimated to have killed a staggering 830,000 people.

Though accurate casualty counts are difficult to establish in the wake of large-scale disasters, especially ones that occurred centuries ago, the death toll wrought by the quake is widely regarded as the largest in a single day.

According to History.com, the quake shook the landscape in the late evening, and aftershocks persisted through to the following morning.

Scientists have since calculated that the quake had a magnitude of around 8.0 to 8.3, meaning it remains some way short of the strongest ever recorded.

Wei River Valley (Image: Getty)

But as it struck in a densely populated area with homes and buildings ill-prepared for the violent movement, the quake caused death on an appalling scale and cause apocalyptic 60-feet crevices to appear in the ground.

According to the outlet, the epicenter was in the Wei River Valley in the Shaanxi Province, near the cities of Huaxian, Weinan and Huayin, a region regarded as the cradle of Chinese civilisation.

Every building and home in Huaxian collapsed with over half of the city's residents killed, number thought to have been in the tens of thousands, with similar outcomes in Huayin and Weinan.

The quake was so powerful that it caused death and destruction 300 miles away from the epicenter and triggered deadly landslides.

The epicentre is thought to have been in Wei River Valley though people hundreds of miles from it were killed (Image: Getty)

The quake lasted just seconds but is estimated to have directly killed 100,000 people, with the remainder killed by landslides, sinkholes, fires, migration, and famine, as per Science Alert.

The most deadly days in the history of warfare killed far fewer than the disaster in Shaanxi. Operation Meetinghouse, a US bombing raid on Tokyo on the night of March 9 to 10, 1945 is thought to have claimed the lives of 100,000 people in Tokyo.

Meanwhile, the atomic bombs American forces dropped only a few months later on the Japanese cities of Hiroshima and Nagasaki are reported to have killed around 66,000 and 39,000 lives, respectively, as per IFL Science.

Meanwhile, the Yangtze-Huai River floods are frequently identified as the biggest natural disaster in history, with fatalities thought to be in at least hundreds of thousands and potentially millions of people, according to National Geographic.