The Square Mile: a Roman outpost that refused to be governed

Cultures · Published 29 September 2026 Swipe more like this →

In short: While much of London expanded into a vast metropolis, the City of London remained a tiny, sovereign anomaly. This 1.12-square-mile enclave, established by the Romans around 47 AD, maintains a unique political status and a government structure that has largely escaped the reforms of the modern era.

The City of London, or the 'Square Mile,' is a historical paradox. Founded as Londinium by Roman legions around 43–47 AD, its boundaries have remained remarkably consistent with the ancient Roman settlement. While the wider London metropolis grew to encompass dozens of boroughs, the City retained its identity as a distinct local authority, governed by the City of London Corporation and led by the Lord Mayor.

Its survival is a story of resilience and strategic autonomy. After the Romans withdrew in 410 AD, the area fell into decay, and the population center shifted west to Lundenwic. It was not until 886 AD that Alfred the Great began the resettlement of the walled area, rebuilding the Roman city to repel Viking raids. Throughout the centuries, the City resisted central authority, most notably during the 1630s when it famously declined the Crown's attempts to extend its jurisdiction—a moment known as the 'great refusal.'

Today, the City serves as a global financial powerhouse, housing the Bank of England and the London Stock Exchange. Despite its small size, it is a massive economic engine, employing over 500,000 people as of 2019. While its resident population has fluctuated—dropping from over 127,000 in 1851 to just 8,583 in the 2021 census—its influence remains immense. It is one of the few places in the UK where the local government structure remains unaligned with the standard 'one vote per citizen' model, a legacy of its uninterrupted corporate integrity since the Anglo-Saxon period.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• The last living remnants of the medieval Duchy of Normandy
• The British enclave that survived the end of an empire
• The German city that refused to fade after losing its capital status
• Why the man on the Clapham omnibus represents the average person in London
• The 1978 Cinema Rex fire: A tragedy that ignited the Iranian Revolution
• From Memphis indie films to viral parodies, the multifaceted career of Clare Grant
• How a failed law student became an Academy Award winner
• How a random bar fight nearly derailed the career of a Scottish pop icon
• Why Oasis used fake crowd noise to sell a song about working-class rebellion
• From horror icon to stage royalty: the versatile career of Clare Higgins
• From Belfast law student to the face of cinematic prestige
• The unpretentious aristocrat who became the grandfather of a modern British queen

More in UK & Irish culture · More in Cultures · Latest · A–Z · All topics