The 76-year-old retired Colonel with 1st Battalion Royal Irish Rangers is an international authority on fortresses and has just published his third book on the Napoleonic Towers in Ireland, Billy Pitt Had Them Built. Married to Sue, he has two grown-up sons and a daughter. Born in Northern Ireland, he now lives in Stamford
I was born in Belfast and lived in Bangor and Whiteabbey. I went to Campbell College and then studied law at Queen's University. I was always going to go into the Army but my parents thought I ought to go and study law and I thought 'why not take four years out?'.
With hindsight I probably should have studied history.
I don't know why I choose the Army as a career; there is no military background in the family apart from an uncle who served in the First World War.
In 1958, I was commissioned into the Royal Ulster Rifles (TA) and later became a regular officer commanding the 1st Battalion Royal Irish Rangers.
I was very fortunate that things fell into place for me and as a result, I have spent time in Malaysia and Borneo with the Royal Ulster Rifles and commanded the 1st Battalion in Cyprus, served under the United Nations banner and in Northern Ireland.
I was defence attache at the British Embassies in Rangoon and Beijing and served in Australia and Gibraltar. I did the full term of 32 years and retired in 1992. I then ran the government estate Dorneywood for 10 years.
I now live in Stamford in Lincolnshire although I still have family in Northern Ireland.
I always had an interest in fortresses. I was fortunate to be stationed at Hyde in southern England and the Martello Towers fascinated me. Then I spent time at the Australian Staff College which was an old defence fort that intrigued me and also in Gibraltar, so I've seen quite a lot of interesting fortifications.
It wasn't until I retired and had time on my hands that I began to take a more serious interest in the topic.
I joined the Fortress Study Group which is an international charity which fosters study in post-medieval fortifications and became secretary of the group and I am now chairman.
We have about 600 members from all over the world, including America and Australia.
I then started to write and finished my first book, Towers Of Strength, and then my second book, Fortifications Of Ulster, which I then revised, and I brought out the Martello Towers a couple of years ago.
I thought there were enough fortifications in Ireland to merit a small book and wrote Billy Pitt Had Them Built. More towers were built in Ireland than in any other country except England.
There were more than 50 Martello towers, 10 Quadrangular towers and 77 signal towers built around Ireland to counter the threat from Napoleon.
The towers cost £250,000 when they were constructed between 1804 to 1817, which is the equivalent today of £50 million.
The new book describes the origins of the towers in Ireland and gives the locations as well as details of the state they are in so it is a bit of a guide book as well.
There is only one Martello Tower in Northern Ireland, at Magilligan Point, and the rest are in the south. Some are well looked after and some sadly have fallen down. Our study group took a tour in the south last May and we had 40 members visiting a number of forts there.
We visited the magazine fort in Dublin which is in a poor state of repair and we were able to get it recognised and now something is being done about it.
We do lobby to have them recognised and protected.
We also visited Fort Camden in Cork where a group of volunteers are doing a great job in protecting it and also Bantry Bay and Beer Island where there is a whole host of fortifications from the late 19th century.
There is a very big interest in military history among a whole series of small groups and the Military Historical Society of Ireland has around 1,000 members and is a very strong organisation.
Fortifications are becoming more important from a tourist point of view. Spike Island in Cork Harbour is a huge fortress which has now been opened up for tourists."
The Fortress Study Group has 600 members including academics, historians, military personnel, architects, engineers and academic institutions and museums worldwide, and others interested in the study of fortifications.
he Group encourages research, study and recording of fortifications and publishes an annual academic journal FORT and magazine CASEMATE.
Bill has written books and articles on fortifications including 'Martello Towers Worldwide' and 'Defending the North: the Fortifications of Ulster 1796-1956'.
He is a Fellow of the Royal Historical Society.
Billy Pitt Had Them Built, published by The Holliwell Press, £12.95, is available from Amazon and all good book stores.