Kent archaeologists discover Sheppey WW1 trenches
It was once known as "Barbed Wire Island": a flat, marshy area in the Thames Estuary that was heavily fortified and bristled with guns in anticipation of a German invasion that never came.
But when archaeologists began excavating the island of Sheppey off the north Kent coast, what they found took them by surprise.
They expected to uncover structures from World War Two, but instead discovered "fantastic" trenches dating back to World War One that they believe to be of national importance.
The network of trenches was just one aspect of a huge security operation centred on the island during war. Residents were issued with "Sheppey passports" and plans were drawn up that would have seen the entire north Kent community facing evacuation and the loss of their livelihoods.
A devastating "scorched earth" policy aimed at hindering and frustrating the invaders would have seen livestock slaughtered and even beer destroyed.
During World War One, the Germans were expected to invade across the North Sea to Kent and the Thames Estuary, with the military ports of Sheerness and Chatham considered prime targets.
About 11 miles (18km) of trenches were constructed on Sheppey, with more on the Kent mainland.
The defensive network included double or triple lines of trenches, with additional communication trenches between the first and second lines, with particularly strengthened areas along the main road from Dover to London.
Simon Mason, principal archaeological officer for Kent County Council, said the defences were similar to those seen in mainland Europe.
"If you can imagine the sort of trench systems you had on the Western Front, they were being replicated in this area as well," he said.
According to local historian Ken Ingleton, who has researched the area's World War One past, the "Barbed Wire Island" nickname was apt.
The Royal Engineers, Kent's local regiment, covered Sheppey's perimeter with it and built mobile gun emplacements along its beaches.
The island, which has had a dockyard since the 17th Century, covers 35 sq miles (91 sq km) and is separated from the mainland by the Swale, a narrow sea channel. In the 2011 Census, its population was 40,300.
According to the Sheppey website, there have been five bridges linking the island to the mainland.
The island now has the new 0.8 mile (1.25km) Sheppey Crossing over the narrowest part of the Swale, but during World War One the island's bridge was a "rolling lift" structure that was first operated by hand and later by electricity.
With Germany increasing its naval fleet, invasion fears grew and the island became a garrison for thousands of troops.
The army took over Sheppey's larger houses and open spaces. Population statistics showed more people moved on to the island, and the dockyard doubled in size to repair and maintain ships.
But Mr Mason said that while the island community grew, military planners prepared for the wholesale evacuation of the north Kent coast and the destruction of farms, communities and businesses.
'Scorched earth policy'
The guns on Sheppey had been designed to turn inland to fire over the towns of Sittingbourne and Faversham.
And if north Kent became the front line of the conflict, the army would have wanted to get the population out of the way as quickly as possible.
Council minutes revealed details of evacuation routes, he said.
"The general principle was to get people away from the coast into the downlands and then move them around to the south of Maidstone, and the south of Redhill, for example, and into the Berkshire area eventually - out of the immediate frontline while bringing the military into this area," Mr Mason said.
The planned "scorched earth" policy saw advice issued to farmers on how to destroy livestock. Faversham's Shepherd Neame brewery would even have been ordered to destroy its beer.
The aim was to ensure the German army would not have been able to live off the land.
Mr Ingleton said the Sheerness dockyard was so important that the whole island became a restricted area, with residents given identity cards known as "the Sheppey Passport".
"It looked like a passport. It had all the information similar to a normal passport, and it also had something like a visa," he said.
To leave the island and return, residents needed to get the document signed by police. "Passports" were checked at the bridge and the railway station.
'Barbed Wire Island'
- At the outbreak of the war, Sheerness and Chatham dockyards were the only naval bases with an outlet to the North Sea, across which a naval attack by Germany would come
- Sheerness played a key role in the defence of the Thames and Medway military ports
- The nation depended on the Thames, as the river artery to and from London, for the import of food and other supplies
- An enemy-occupied Sheppey would have offered a base from which to launch an attack on the Kentish mainland as well as a place from which to blockade the river
It was the only time in Sheppey's history that permits were issued.
"In the Second World War, although there was a degree of restriction, they didn't actually issue passports to the island again," said Mr Ingleton.
Mr Mason said the north Kent trenches were thought to be the only ones in England built for defence purposes, rather than training.
"What we've actually found is a fantastic set of World War One remains in the borough, something which we just really didn't know about beforehand," Mr Mason said.
"The way in which defensive arrangements were put in place within this country has been often overlooked, and overlooked even amongst the experts.
"We were really surprised by what we found."
Excavations of the World War One trenches are taking place this month by a team of archaeologists and volunteers from CSV from BBC Radio Kent.