London's first Mayor, Ken Livingstone, had a term that was littered with achievements - and missteps - that came to define his tenure. His successes were numerous: creating the London Overground, pedestrianising Trafalgar Square, winning the Olympics and commissioning the London bike hire scheme. His best known legacy though is probably the Congestion Charge - a controversial scheme environmental scheme that has come to last well into a Tory Mayor's reign, albeit in a smaller form.
The current Mayor will have a quite different legacy, and one, ironically for a political leader known for inaction rather than action, will be far more dramatic and long-lasting than his predecessor's.
The statistics that pop up in the media with increasing regularity tell a story that we all know. London is unaffordable. It is the city of foreign billions, of buy-to-leave properties; of hedge fund millions and gleaming towers of global wealth. It is a city where three-quarters of new homes are sold to overseas investors, the majority with no inclination of ever living in it, of supporting its businesses or giving it life - a city where the most 'desirable' central boroughs are seeing a 40% rise in empty homes as a result. A city whose every new development reduces affordable housing and builds homes for the rich. It is a city whose housing and rent costs are driving its new residents to its peripheries and, for many more, away altogether.
London is, as one estate agent put it, a city where "rich and poor can no longer live cheek by jowl". Mayor Boris Johnson, through ending a commitment to affordable housing and supporting endless developments aimed only at the rich, is destroying one of the defining characteristics of London - its social diversity - that set it apart from so many other global cities. He is ending the chances of millions of young (and not-so-young) people to live in the city in which they work. And in time, this will drive away the many businesses, cultural centres and organisations that give London its life.
All that will remain will be a soulless metropolis of glass towers and empty mansion blocks. And for that, Boris legacy should become known for the poisonous one it is: as the man who took a great cosmopolitan city of villages and turned it into the bank account of the super-rich. The man who will leave the city poorer in human terms, despite all the billions flowing around its properties.