He said: "My passion grew out of an incident on my first day as a Saturday boy at Sanders. A piece of plaster from the ceiling fell on my head as a result of refurbishment works at Oriel College next door. When the manageress complained, the college forked out enough to pay for a new map department. The manageress called me the mapping manager even though I was only a Saturday boy."
After university he joined the book department of Bonhams auction house before going on to set up the map and atlas department at Bernard Shapero Rare Books in London.
He hit the headlines in 2007 when he sold an atlas for £2.1 million - the highest price ever paid - and sold a map for $1 million two years later, before setting up his dealership, Daniel Crouch Rare Books.
He acquired the 1574 map from a private customer, the way he makes 50 per cent of his acquisitions, with the rest coming from dealers or bought at auction. He is showing it at the Mapping London exhibition which runs until September 14.
Precious as the London map is, there is one Mr Crouch longs to own even more. "It's the first printed one of Oxford circa 1575 by Ralph Agas. The only known example is in the Bodleian Library and they aren't selling," he said.
