It’s inevitable that many of these locations feature as castles belonging to John of Gaunt: Tutbury, Leicester, Herefored and Hertford to name a few. I’ve also included a few places associated with Mary de Bohun whose household Katherine is listed in during some of the period when she and Gaunt went their separate ways.
Double click on the pointer to open up a box with a snippet of information about each of these locations. If nothing else it is possible to see how widely travelled John of Gaunt was within England. It is possible to see the lines of Roman roads as well as the marches between England and Wales as you look at the locations, a reminder that in the past boundaries determine fortifications and that key transport networks made it possible for the great and the good to administer their estates.