Modern-day Britons, as some archaeologists like to call them, are characterized by the use of bronze and iron, both of which became prevalent around 2700 BC and 700 BC, respectively. It is believed that the discovery of bronze was at approximately 2100 BC, and that at approximately 700 BC, iron working skills were developed which further allowed for the expansion of the now cities and towns. Bronze lead to the use of better and better tools which could withstand repeated pounding and usage, and iron, which is even stronger than bronze, was leveraged by cities and leaders to build even more dynamic structures and cities.