Having thoroughly enjoyed your books over the years, I have just read Azincourt and yet again had great pleasure in the process. I am the information officer for a local heritage group working in the Yorkshire Dales and one of the fascinating sections of the book dealt with the mining operation to “undermine” the defences of Harfleur. We have carried out research work on so called “sow”kilns in the limestone areas of the Pennines and for the first time I understand the connection as these are smaller versions of military earthwork feature but minus the mine adit. I’ve had an unsuccessful attempt at finding any historical references to the sow you so clearly illustrate and wonder if you may point me in the correct direction? This would be really appreciated as the reason for the sow bit of the kiln name has, up to the reading your book, been a mystery. Many thanks. Phil Carroll (Our group website is www.uwhg.org.uk – Upper Wharfedale Heritage Group a Dales valley a little further south than the one featured in some of your earlier writing)