“While Caesar officially announced his intention was to pacify the Britons and cut off their aid to Gaul we do have primary source evidence that demonstrates a more economic motive for the invasion.”

By Nicklaus Bobertz

History teaches that Julius Caesar invaded the British Isles in 55 BC based on a suspicion that the Britons were supporting the Gauls in their fight against Rome.

Yet, there may be another reason for the decision to land armies on Britain’s shores: vast deposits of the metal ore tin that were long believed to be there.

But why would Julius Caesar care about tin in particular?

By the time of Caesar’s invasion of Britain, the Roman Republic had transitioned from the Bronze Age to the Iron Age. But of course that didn’t mean that bronze was no longer of value.

Bronze is an amazing alloy that is created by combining copper and tin in precise quantities. The Romans would then turn this bronze into sculptures.

Easily the greatest of these sculptures comes from the reign of Emperor Nero about a century later. Nero’s bronze statue of himself was called the Colossus and stood at an astounding 31 to 36 meters high.

Unfortunately, nearly all of the bronze sculptures created during the Roman Republic and Empire do not survive. They would be melted down as the Empire declined.

More importantly, tin would allow Caesar to mint more Roman coins. In theory the general could have become insanely wealthy from his capture of Britannia.

So there may have been more than just the drive for military glory behind Caesar’s conquest. However, do we have any primary sources detailing his expedition as having an economic motive? Turns out, we do.

About 300 years before the time of Julius Caesar an ancient Greek explorer named Pythaes visited the British Isles sometime between the year 320 to 306 BC.

Pythaes lived during the height of Greek culture and exploration. He was born and lived in the ancient Greek colony of Massalia which is today the French town of Marseille. This Greek colony was located on the Mediterranean coast of France and was a vital trading post for Gallic goods being exported around the Greek world.

Pythaes decided he wanted to explore the furthest regions of the north. Writing about his tales he would be the first continental European to visit the British isles.

While visiting the British Isles, Pythaes encountered the residents of Cornwall. He wrote detailed accounts of how the entire population of there was engaged in mining and manufacturing of vast amounts of tin ingots.

Unfortunately, none of Pythaes works survives to our modern day. However, we do have other sources such Strabo’s Geographica that cite Pythaes’s work.

What this means is that the Romans of Julius Caesar’s time knew of the vast mineral deposits of Britain. Further, ancient writers such as Plutarch detail how many Romans saw Caesar’s voyage as foolish as they doubted Pythaes’ account.

While Caesar officially announced his intention was to pacify the Britons and cut off their aid to Gaul we do have primary source evidence that demonstrates a more economic motive for the invasion.

The first comes from Julius Caesar’s autobiography Commentarri de Bello Gallico. This book details Caesar’s conquests of Gaul and Britain over a period of nine years.

Within the volume there is an account of the economic activity by the native Britain’s after Caesar pacified them. Caesar noted that the locals mined and exported quantities of both iron and tin somewhere in the midland regions of Britain.

The next primary source comes from the city of Rome itself. Caesar’s contemporary politician Cicero wrote a letter to a friend detailing the poor results of Caesar’s conquest. Cicero hoped that Britain would be filled with gold and silver. It wasn’t.

As we can see even the politicians in Rome believed that there was an economic motive for Julius Caesar’s invasion.

Julius Caesar’s motivation to invade Britain continues to be debated. The official account provided by Caesar is that the Britons were ‘helping’ the Gauls to rebel. However, when historians look closer we can see economic motives behind the invasion, namely tin.

Nicklaus Bobertz holds a master’s degree in history from the University of Central Florida in the United States. He has been published in Cambridge University Press and has presented at the University of Toronto. He is the publisher of TheHistoryAce.com where he aims to explain complex history topics in an accessible manner.