Greater London Authority
London is a coral reef—a living structure that took centuries to build and now supports an entire ecosystem of financial species that couldn't survive elsewhere. The City of London Corporation, governing the ancient Square Mile, is the reef's calcified core: medieval governance structures (the Lord Mayor, the Livery Companies, the Court of Common Council) that provide the stable substrate on which modern finance grew. Like an oyster reef that filters water for an entire estuary, the City clears transactions and sets legal precedents that shape global commerce.
Preferential attachment explains how London became what it is. Once established as a financial hub after the 1688 Glorious Revolution, every new institution—Lloyd's coffee house (1688), the Bank of England (1694), the Stock Exchange (1801)—attached to the existing structure because that's where the other fish already were. By 1900, London cleared 60% of world trade. Network effects made it irreplaceable: legal expertise, clearing infrastructure, and professional networks that couldn't be replicated elsewhere. The City became the hub in Britain's hub-and-spoke economic geography, with Manchester, Birmingham, and Leeds as dependent spokes.
Brexit was an attempt to relocate the reef. The results are mixed: Lord Mayor Michael Mainelli estimates 40,000 jobs lost since 2016, with Dublin gaining 10,000, Paris and Frankfurt dividing the rest. Yet Euro-denominated clearing stayed in London, Goldman and Morgan kept their main trading floors in Canary Wharf, and worker numbers have swelled to 615,000 as insurers and data analytics companies expanded. The reef is stressed but regenerating—2025 saw 11 IPOs raising £1.9 billion, the strongest year since 2021.
The keystone species (HSBC, Barclays, Lloyd's) had too many symbiotic relationships to sever. But London's dominance creates pathology: the city generates 23% of UK GDP with 13% of the population, creating source-sink dynamics that drain talent from other British cities while raising housing costs that make London unlivable for anyone except the already-wealthy.
The City of London Corporation is not part of Greater London Authority governance—it's a separate entity with its own police force, its own Lord Mayor, and voting rights for businesses as well as residents. The Square Mile's medieval constitution was never reformed because successive governments feared disrupting financial stability.
Key Facts
Power Dynamics
Mayor of London controls TfL, Metropolitan Police oversight, strategic planning; 25-member London Assembly provides scrutiny; boroughs retain local planning and services
City of London Corporation operates independently with enormous lobbying influence; major banks can threaten relocation to extract policy concessions; TfL fare revenues give Mayor real fiscal power; housing crisis forces national government attention
- City of London Corporation (financial regulation)
- Borough councils (local planning)
- Westminster (devolution limits)
- Treasury (fiscal policy)
- HM Treasury
- Bank of England
- Major clearing banks
- Property developers
- Transport unions
Failure Modes of Greater London Authority
- 1666 Great Fire - destroyed medieval city, enabled planned reconstruction
- 1940-41 Blitz - heavy bombing but financial center survived
- 1992 Black Wednesday - sterling crisis exposed limits of UK monetary independence
- 2008 financial crisis - required £500bn bank bailouts
- 2016-present Brexit - 40,000 financial jobs relocated to EU
- Brexit-induced financial migration (7,500 jobs by 2023)
- Housing costs making city unaffordable for non-wealthy
- Infrastructure aging (Victorian sewers, overcrowded Tube)
Euro clearing relocated + property crash + regulatory divergence = financial sector tipping point
Biological Parallel
Coral reefs take centuries to build but support ecosystems far richer than their surrounding waters. London's financial infrastructure—legal frameworks, clearing houses, regulatory expertise, professional networks—accumulated over 300+ years and now supports a financial ecosystem that couldn't exist in a city built from scratch. Like coral, London's value is mostly the accumulated structure, not the current activity.