I have a series of books featuring Master Mercurius, a lecturer in moral philosophy at the University of Leiden in the Netherlands.
Mercurius was born in 1638, so he is 33 at the time of the first story, Death in Delft. We know very little about him except that his mother and grandmother are still alive when the series starts, but that his older brother, Laurentius, was killed at the Battle of Lowestoft in 1665.
Mercurius has a secret – you’ll have to read the books to find out what it is!
Readers of Death in Delft may find this map helpful.
And here is a map of Utrecht that may help with parts of Untrue till Death.