What are some of the most important inventions from the Middle Age?

4. Verge escapement/mechanical clocks replaced hourglasses

The development of the verge escapement would lead to the creation of the first mechanical clocks in around 1300 AD. By the 15th century, they had become widespread around Europe.

They would become the standard timekeeping device until the pendulum clock was invented in 1656.

5. Paper 'money' is older than you think

Although paper "promissory notes" had been in existence for centuries, the first recorded use of government-issued paper money was in 9th Century China. These notes were a promise by the ruler to redeem them later for some other object of value, usually coin. These early credit notes were usually for a limited duration. They were intended primarily for merchants, to replace the need to carry around quantities of metals that were very heavy, and could easily be lost or stolen.

By the 1120s, the Chinese government had started to produce its own state-issued paper money using woodblock printing, and these were in widespread circulation.

Travelers brought news of the government-issued Chinese paper currency back to Europe in the 13th century, but the notes wouldn't become common in Europe until the late-1600s.