Solution:

The history of aluminium has been shaped by usage of alum.

The first written record of alum, made by Greek historian Herodotus, dates back to the 5th century BCE.

The ancients are known to have used alum as a dyeing mordant and for city defense.

After the Crusades, alum, an indispensable good in the European fabric industry, was a subject of international commerce; it was imported to Europe from the eastern Mediterranean until the mid-15th century.

The nature of alum remained unknown. Around 1530, Swiss physician Paracelsus suggested alum was a salt of an earth of alum.
In 1595, German doctor and chemist Andreas Libavius experimentally confirmed this.

In 1722, German chemist Friedrich Hoffmann announced his belief that the base of alum was a distinct earth.

In 1754, German chemist Andreas Sigismund Marggraf synthesized alumina by boiling clay in sulfuric acid and subsequently adding potash.