How a death saved Europe from the Mongols

The year was 1241 AD. The Mongols have created the largest empire in the World. Batu Khan, son of Ögödei (and grandson of the already deceased Gengis Khan) is leading the Mongol advance.

Domesday Books

In 1085, King William I of England was interested to know who owns which land. He ordered a survey of almost the entire country in which this was settled once and for all.

The invention of 0

While the concept of zero has been around during Babylonian times or perhaps even earlier, the Indian mathematician Brahmagupta (598-665) was most likely the first to write down how to calculate with a zero. He established rules such as 1+0 = 1 and 1-0 = 1; and 1×0 = 0. Interestingly, he wasn’t as sure as we are now, whether …