In The Brampton Witch Murders, Mr Pepys’s personal inquisitors are off to Brampton in Huntingdonshire in September 1666, where his sister has been accused of witchcraft. They take a hackney coach to Cripplegate, following London’s old Roman wall, to catch the stagecoach to Huntingdon – while the great fire of London is raging. (That’s another story.)

My quandary here, while writing the sequence, was: what did Cripplegate look like around that time? The vast stone structure itself is long gone, having been demolished in 1760. Which was when I chanced upon a frankly sumptuous map of London from the late 17th century, attributed to the Czech (then known as Bohemia) artist, Wenceslaus Hollar.

What you see there is a tiny detail of said map, which covers both the Westminster and City of London, decorated with illustrations of the city’s most resplendent architecture – White Hall, Covent Garden, the Royal Exchange, among others – and its old gates: Bishops-Gate, Ald-Gate, Moore-Gate, Lud-Gate, New-Gate, Alders-Gate and, last but by no means least, Cripple-Gate.

If you’ve visited London, those names may be familiar. I lived there for more than 25 years, so they’re very familiar to me (there’s a fabulous curry house in Aldgate – drop me a line if you’d like to know its name). But, of course, it’s all very different now. To see just how different, visit this site, which guides you on a walk around the ghost of London wall.

No one knows for certain from where the name Cripplegate derives. One take that it’s from the Anglo-Saxon word crepel, meaning covered passageway; another, that it refers to the ‘cripples’ who used to beg in the area. Most importantly for me – that’s what it looks like, and I can describe the crenelated towers, windows and portcullis. (Did I mention the portcullis in the book? I don’t remember. Anyway, it’s there.)

I would go on to talk about the artist himself, Wenceslaus Hollar, who was a fascinating character. However, I’ll be returning to him at a later date, so for now I’ll just add that he fought as a royalist at the seige of Basing House, where he was captured by the roundheads in 1645.

When I was a teenager, I used to go metal detecting in the grounds of the ruined Basing House! There, I found a handful of actual English Civil War lead musket balls, one of which might even have whizzed past Hollar’s ear. Honestly, it’s crazy to think now that that man trod the same fields I was walking.

So today’s rabbit-hole link is to the full version of Wenceslaus Hollar’s London map. I recommend you download the largest file size, to fully appreciate its intricacies.