Late medieval London was, like contemporary London, the greatest city of the realm, a center of power, finance, trade, and culture. It mythologized itself as Troynovant, ”.e firste citie of Brettayne,” built by Brutus. And yet the depredations of time – or, specifically, of fire, bombing, and redevelopment – ensure that medieval London is barely visible today. There are, of course, two world heritage sites, the Tower of London and Westminster Abbey, bookending the city to east and west. But most of medieval London is hidden, or glimpsed in passing, or a trace of something lost, or virtual. The City's street plan is still substantially medieval: the stone or glass palaces of the financial institutions cluster on streets named for medieval parishes and commodities. Medieval material survives underground, in crypts and cellars; lost buildings such as Baynard's Castle are commemorated with blue plaques. Or one might see, momentarily, a medieval illusion: from the corner of an eye misrecognize Renzo Piano's ultra-modern Shard (completed in 2013) as a scaled-up church spire. Seeing medieval London takes effort, imagination, luck, or knowledge. The city offers chance, routine, and quotidian encounters with the Middle Ages, of which its inhabitants and visitors might not even be conscious. Bruno Latour writes of the packaging of time into mate rial culture, “Time is always folded. […] Action has always been carried on thanks to shifting the burden of connection to longer- or shorter-lasting entities.” The past acts on the present through material things: in London, the medieval past acts upon the present even in the absence of those material things, operating through the spaces where they were. If I walk from London Bridge to the Strand, for example, I follow much the same route as I would have 600 years ago, though what I see is almost entirely different. The medieval city thus acts on me, through me, as it determines my steps, whether I remember to think so, or not.