A 91-year-old war veteran from Harrow Weald has become one of the world's oldest PhD recipients. The degree was awarded by Cambridge University.
Colonel Michael Cobb lined up alongside students young enough to be his grandchildren at the famous university's Senate House to receive the accolade earlier this month.
He earned the award for his work The Railways of Great Britain: A Historical Atlas, which records and maps every station and every line ever built by the railway companies of Great Britain between 1807-1994.
Speaking about the ceremony, the former Second World War soldier said: "It was very exciting. Forty members of my family came and we all had lunch together at Magdalene.
"It was nice for my grandchildren to see that someone of my age can produce something like this. I can't get over it really."
The award came exactly 70 years after he first graduated from Cambridge's Magdalene College with a degree in mechanical sciences in 1938.
After graduating, he joined the Army as a regular officer, was sent to Europe in 1940, and was rescued on the last boat to leave Dunkirk.
Five years later he began surveying for the Army, commanding survey regiments in Egypt, and continued to do so elsewhere before he retired from the Army in 1965 and from mapping in 1971.
As a lifelong train enthusiast he travelled on all of Great Britain's railway lines between 1950 and 1960 and began work on the atlas in 1978.
The father of three said: "I told the publisher it would take all of my present life and half of my next to finish it, but here we are.
"I was 62 when I started and never even thought of a PhD. In fact, I still don't regard myself as an official PhD really.
"I did this in my own time, no one was chasing me. I went to look at stations for five years, but otherwise it's all from the history books."
From start to finish it took him 18 years to complete and 25 years in total before it appeared in print in 2003.
The former Harrow School pupil is the oldest person to have received a PhD from Cambridge and is believed to be the third oldest person ever to have receivesd one from anywhere.
The current record holder is The Rev Edgar Dowse who received his from Brunel University in 2004 at the age of 93.
Copies of Mr Cobb's work are available at the publisher's website www.ianallanpublishing.com