The Square Mile: A 957-Year Jurisdictional Experiment

The City of London is not London. That sentence is true in a way that sounds like a riddle, and it has been true for nine hundred and fifty-seven years.

The Greater London you arrive in by train is a postwar administrative unit of thirty-two boroughs covering about six hundred square miles and home to roughly nine million people. The City of London is a single square mile inside it, with about eight thousand residents and five hundred thousand weekday workers, and it operates under a separate legal and electoral system from everything around it. It has its own court, its own police force in different uniforms from the Metropolitan Police, its own franchise that lets businesses vote alongside residents, and its own ceremonial head of state called the Lord Mayor, who is not the same person as the elected Mayor of London. The City has been continuously self-governing since 1067. It is the longest-running constitutional anomaly in the British state.

The interesting question is not how it started. The interesting question is why every English government since has decided to leave it alone.

The 1067 charter

William the Conqueror took England in October 1066 by winning a single battle at Hastings. The country he had to govern in the months after was hostile, unfamiliar, and large. London, then a Saxon city of perhaps ten or fifteen thousand people, was the largest settlement in the country and the wealthiest, and it was not interested in being conquered.

William's solution was a compromise the rest of England did not get. Within a year of his coronation at Westminster Abbey, he issued a short written charter, only about seventy words long, addressed to the bishop, portreeve, and burgesses of London. It guaranteed that the city's customs and laws would remain as they had been under King Edward the Confessor. The Normans took the country. The City of London was permitted to keep itself.

The charter was a practical decision. London's wealth depended on its trading and customs networks. Disrupting them would have cost the new Norman crown more than the political price of permitting an exception. The same calculation has reappeared every time the question has come up since.

The medieval consolidation

By the thirteenth century, the City had a corporation, an alderman for each ward, a court, a sheriff, and a Lord Mayor. The Lord Mayor's Show, a procession that the new mayor still rides every second Saturday in November, dates from 1215. The same year King John signed Magna Carta, in which clause thirteen explicitly preserved the City's ancient liberties.

The City's wealth in this period came from the trading guilds: the Mercers, Goldsmiths, Fishmongers, Drapers, Skinners, and dozens of others. These were not informal associations. They controlled who could practise a trade, what quality of goods could be sold, and which apprentices could rise. They were also the City's electoral base. The Lord Mayor was elected by the senior members of the guilds, called Liverymen, and is still elected this way today. The City's electoral system therefore preserves a fourteenth-century commercial republic inside a twenty-first-century state.

The seventeenth-century stress test

Two events nearly destroyed the City: the Great Fire of September 1666, which burned four-fifths of the buildings inside the wall, and the Glorious Revolution of 1688, which restructured English government. The City survived both with its institutions intact.

The Fire actually consolidated City power, because the Rebuilding Act of 1667 gave the Corporation legal authority to direct the reconstruction. Christopher Wren designed fifty-one new churches and the new St Paul's, all on land owned and licensed by the City. The Monument to the Great Fire, designed by Wren and Robert Hooke and finished in 1677, is a City monument on a City spot, paid for by City taxes.

The 1694 founding of the Bank of England was the second consolidation. Parliament chartered the Bank to raise war finance for William the Third, but the Bank was based in the City, run by City merchants, and answerable to the City's commercial culture. From that point on, the British state and the City were structurally bound. The state needed the City's capital. The City needed the state's stability.

The nineteenth-century survival

Every reform of British government in the nineteenth century carved out an exception for the City. The Great Reform Act of 1832 redrew Parliamentary boundaries everywhere except inside the Square Mile. The Municipal Corporations Act of 1835, which reorganised every other English town's local government, exempted the City. The 1888 Local Government Act, which created the London County Council to administer the rest of the metropolis, exempted the City.

The pattern is the same in each case. Reformers proposed absorbing the City. The City's commercial and political weight made the proposal more costly than the principle, and the exemption survived.

The most serious modern threat came in 1963, when Greater London was created by combining the London County Council area with surrounding suburbs. The bill that did this contained a brief debate about absorbing the City. The City was permitted to keep its corporation, its police, its court, and its Lord Mayor. The 2007 Greater London Authority Act made the same decision again, this time with a Greater London Mayor as an elected position. The two mayors now coexist. They have separate jurisdictions and meet ceremonially.

What you can see on the ground

The jurisdictional boundary is invisible if you don't know it. Walk west from the Tower of London along Eastcheap. Somewhere around Mark Lane you cross into the City. There is no sign, no line, no change in the street. The police officer at the next corner is wearing a slightly different uniform from the one half a mile back, and that is the only visible cue.

The boundary asserts itself architecturally in a few places. At Temple Bar on Fleet Street, the western edge, a 1672 stone gate once stood where the monarch was required to ask permission of the Lord Mayor before entering the City. The gate was removed in 1878 for traffic and reinstalled at Paternoster Square next to St Paul's in 2004. The custom of asking permission has been preserved. When Charles the Third entered the City as monarch in 2022, the Lord Mayor handed him the City's Sword of State, point-down, as a symbol of submission to the City's authority within its own walls.

The Lord Mayor's Show every November is the public theatre of the same logic. The procession runs from Mansion House, the Lord Mayor's residence, to the Royal Courts of Justice, where the new Lord Mayor swears loyalty to the Crown. The route is the boundary of the City, walked once a year so everyone can see where it goes. It has been walked every November since 1215.

Why the anomaly is interesting

The City of London is not an inefficiency in the British state. It is a deliberate feature. It exists because every British government has concluded that allowing one square mile to govern itself produces more revenue, more financial stability, and less constitutional friction than absorbing it would. The arrangement is not democratic in the modern sense. It is older than modern democracy and has outlived several iterations of it.

The City of London tour walks the experiment itself: the Tower built to subdue the city, All Hallows that predates the Tower by four hundred years, Pudding Lane where the fire began and the rebuilding charter was signed, the Monument that consolidated City pride, Leadenhall Market on the Roman forum, the Bank of England, and St Paul's. Walking them in order is walking the chronology of how an anomaly held. The Square Mile is not a museum. It is a working jurisdiction, doing the same job, in the same way, for the nine hundred and fifty-seventh consecutive year.