Despite this reverence for the past, parliament eventually needed to step in to prevent certain places being lost. While a few important sites were protected by law by the end of the 19th century, it took the 1913 Ancient Monuments Amendment and Consolidation Act to revolutionise how we view and secure the physical remains of our history.

I ask Thurley (pictured right) why the act was needed at that time. “It’s a very modern notion for the state to get involved in heritage protection things, and interfere with people’s private property”, he says. “Before this there was a pretty solid consensus against it – not really surprising when you think that parliament in both houses was dominated by people who owned land. Certainly in the 19th century, land ownership was one of the criteria that got MPs elected, so why would you vote to restrain your own activities?

“Things did change, though, particularly as the industrial revolution progressed. By the 1830s and 1840s, it’s pretty clear to people that industrialisation is ugly; it’s destructive; and a blight on the landscape. The amount of destruction wrought by the coming of the railways in particular was unbelievable.

“This groundswell of concern came to a head in the early 20th century because of the fashion for Tudor and Stuart architecture in America,” he continues. “American collectors wanted to buy up bits of English houses and castles, and build them into their houses in the US. Consequently, a huge transatlantic trade in architectural features developed. Sometimes just individual features like fireplaces, doors and columns – but often whole rooms, and sometimes whole buildings.

“One case in particular triggered the act: Tattershall Castle in Lincolnshire. This was sold by its owners, and the fireplaces were offered to dealers who intended to ship them to America. They didn’t get that far: the fireplaces were saved before they got on the ship, but it caused quite a flurry.

“Very quickly, an act of parliament was passed, which for the first time made it possible to protect a building like Tattershall from speculation. For the first time, parliament accepted that the property rights of an individual could be constrained by the state in the greater interest of everyone else.”

But there had been three previous protective acts – in 1882, 1900 and 1910 – which were seen as inadequate. What then, I ask, did the 1913 act offer that its predecessors didn’t?

Says Thurley: “It introduced the concept of making a list of what’s important and needs to be protected. Secondarily, it introduced the concept of building up a collection of places that could then be used to educate people about the importance of British history.

“The idea was to tell the story of the nation. But in 1913 people’s perception of what constitutes history was different to that of today. Then, it was very much divided into two sections: the Reformation, which made England a Protestant country; and the Civil War, which was seen at the time as having established ‘the land of the free’, as well as parliamentary democracy. These two landmark events did, of course, produce some of our greatest monuments. They produced many of the ruined abbeys and castles we see today.

“Nowadays, however, many people see history as being the story of workers and ordinary people, and our collection reflects that: it even includes mills and factories from the ‘destructive’ industrial revolution era.

“Right the way through the interwar period, after the Second World War, the 1960s and 1970s, and even after the ancient monument branch became English Heritage in the 1980s, there was a strong feeling that the gaps that existed in the collection needed to be filled to tell the whole story.

“One example,” continues Thurley, “is Harmondsworth Great Barn on the edge of Heathrow airport. This is the greatest medieval barn in England, the like of which is not in public ownership anywhere.

“Like many acquisitions, the story of the barn is a sad one. It was purchased by speculators when it was thought Heathrow airport was going to be extended, and it was clearly going to be used as a sort of ‘bargaining chip’. The land that went with the barn was gradually sold off, but the barn itself was left to fall into terrible disrepair. When English Heritage told the owners they had to repair it, they refused, so we did the work and sent them the bill. They went bankrupt and we acquired the building.”

Clearly the challenges that English Heritage faces are numerous, varied and ever-changing. What, I ask Thurley, are the biggest threats faced by our ancient sites today?

“Since the Second World War, the single most destructive force against England’s heritage has been agriculture. Something like 20 monuments a day have been destroyed by agriculture since the war. It’s unbelievable. A countryside that in 1939 was full of the ancient humps and bumps of the prehistoric world was wiped out in a generation. The mechanisms to protect our heritage are only just catching up and starting to save sites.

“Fortunately, one of the big agricultural changes that has taken place is the ability to get subsidies for environmental improvement. Heritage is a major part of this: stewardship schemes go for nature conservation but also for heritage.”

I’m curious to know when, for English Heritage, a site becomes old and important enough to be considered for the collection. What, for instance, is the most modern place in the collection?

“When I arrived at the organisation, we had two offices in York,” says Thurley. “In the garden of one of these we found a nuclear bunker that had been built for the Royal Observer Corps. These were volunteers who were tasked with the job of going into this bunker and measuring the amount of radiation in the air in the event of nuclear war. A network of similar bunkers existed all over the country, but amazingly we found one in the garden of our office! I think there is one other in existence. We are the proud owners of a Cold War nuclear bunker! It’s our most modern site.”

What, though, is Thurley’s favourite site? Here he is loath to single out any individual English Heritage location. He does, however, tell me about his favourite walk to one of the most impressive castles in the collection.

“I live on the coast and I am mad about it,” he says. “The best walk is to Dunstanburgh Castle. You can only reach it by walking; it’s an incredibly wild place high up on the Northumberland coast. It’s a heartbreakingly beautiful spot.”

10 places in England’s history

Stonehenge, Wiltshire

One of the world’s most famous prehistoric sites

Stonehenge, one of Britain’s most famous and mysterious man-made structures, was last sold on the open market in 1915. Fortunately, its buyers, Cecil Chubb and his wife, gifted the entire site to the nation three years later and it thankfully remained open to the public. Set in glorious chalk downland and surrounded by barrows, prehistoric ditches and other monuments, the c5,000-year-old site has been blighted by two busy main roads – the A303 and the A344. By the end of this year the A344 will be closed and a new visitor centre will be opened by English Heritage. By summer 2014, skylarks will sing above the former road and the landscape will have a more evocative look and feel. 0870 333 1181 www.english-heritage.org.uk/stonehenge

Housesteads Roman Fort, Northumberland

An iconic fort on Hadrian’s Wall

Housesteads Roman Fort in Northumberland garrisoned up to 1,000 infantry at its peak. It is one of the most complete Roman forts in all of Europe. The site continues to yield secrets about the lesser-known, but equally gripping, lives of civilians who followed, supplied and depended on the Roman army. Owned by the National Trust, the 2.2-hectare site was seen as a vital part of the nation’s story, and was taken under the wing of the Ministry of Works in 1951 (and later English Heritage). Much of the rest of Hadrian’s Wall remains in private ownership. 01434 344363 www.english-heritage.org.uk/housesteads

1066 Battle of Hastings, Abbey and battlefield, East Sussex

Where William the Conqueror triumphed in 1066

This site marks one of the great turning points in English history. The abbey was built by William the Conqueror in thanks for his victory over Harold II and the Saxons in 1066. Though little of the original abbey still stands, other Norman architecture survives, including the gatehouse and courthouse. From the abbey terraces, visitors can look out over the battlefield and see the hill where the Saxons stood, initially resolute, until they broke ranks to follow the feigned retreat of William’s men. The abbey was dissolved in the 1530s and the estate was bought by the Department of the Environment in 1976, helped by donations from a group of Americans celebrating the bicentenary of American independence. 01424 775705 www.english-heritage.org.uk/1066

Dover Castle, Kent

Known as ‘the key to England’

For anyone approaching England from the nearest point in continental Europe, the imposing keep of Dover Castle is, in its role of defender of the shores, the perfect embodiment of the story of England. Once an Iron Age hillfort, Roman stronghold and Saxon fort, it stayed in military use until after the Second World War. It was besieged by the French prince Louis in 1216, but withstood the assault. In the Cold War it was intended to be a regional seat of government in the event of nuclear attack. It came completely under English Heritage management in 1991. 01304 211067 www.english-heritage.org.uk/dover

Rievaulx Abbey, North Yorkshire

One of England’s first Cistercian monasteries

Founded by the Cistercian order of monks in the 12th century, Rievaulx and the nearby abbeys of Fountains and Byland are wonderful examples of early English Gothic architecture. Although its monks were banished during the dissolution of the monasteries in the 1530s, the abbey was not destroyed. The buildings subsequently fell into ruin until its owners, the Duncombe estate, placed the site in the care of the Office of Works in 1917. The crumbling walls were rebuilt and strengthened to recreate a real sense of what this extraordinary religious building looked like at its height. The setting and spectacle are magical. 01439 798228 www.english-heritage.org.uk/rievaulx

Kenilworth Castle and Elizabethan garden, Warwickshire

Once the home of kings

At the centre of English history throughout the Middle Ages, Kenilworth Castle was home to King John; Simon de Montfort (who led the barons’ rebellion against Henry III in the 13th century); kingmaker, troublemaker and prince of the realm John of Gaunt (third son of Edward III); and Robert Dudley, suitor of Elizabeth I who stayed at the castle several times during her reign. The most spectacular additions to the castle, including the great palace (the hall of which still stands), were built by John of Gaunt. Ruined in the Civil War, Kenilworth Castle has survived down the centuries but was eventually bought for the nation by philanthropist Sir John Siddeley in 1937. 01926 852078 www.english-heritage.org.uk/kenilworth

Audley End House and Gardens, Essex

A palace in all but name

The magnificent palatial residence that survives today is just two-thirds of the inner court of what was once Britain’s largest private Jacobean house. Built between 1603 and 1614 by Thomas Howard, Earl of Suffolk, who rose to prominence under James VI & I, Audley End is the architectural manifestation of a strutting courtier bathed in royal patronage. Ruinously expensive to maintain, Audley End was sold to Charles II in 1666 and became a royal palace for a while. Sold to the nation in 1948, it is the perfect place in which to get a feel for the Jacobean and Stuart periods. 01799 522842 www.english-heritage.org.uk/audley

The home of Charles Darwin, Down House, Kent

The former home of a ground-breaking scientist

The significance of this property lies almost entirely with its historical resonance rather than any unique architectural qualities. Between 1842 and 1882 it was the home of Charles Darwin, and the place where he wrote On the Origin of Species and other great works. Sold by the Darwin family in 1907, the house slowly decayed under a series of owners until it was bought by English Heritage in 1996. The property has since been restored to how it looked when Charles Darwin lived there, and the house and surrounding gardens give an emotive insight into the great man’s life and thinking. 01689 859119 www.english-heritage.org.uk/darwin

Wrest Park, Bedfordshire

England’s largest ‘secret garden’

Previously overgrown and largely forgotten, Wrest Park is now widely regarded to be one of England’s greatest 18th-century gardens. It belonged to the de Grey family from the medieval period until the 20th century and the family commissioned many of the most famous Georgian designers to work on the landscape. But whereas in other gardens the previous designs were lost in the pursuit of new gardening vogues, each generation at Wrest Park respected the work of their predecessors. As a result visitors can walk through 300 years of English garden history. The house was built in the 1830s in the style of a magnificent French chateau and retains many of its original charms. During the First World War it was used as a military hospital. In 2006, English Heritage took over the management of the house and gardens and embarked on a 20-year plan to peel back the layers of over 300 years of garden history. Visitors today can see that the plans are already bearing fruit. 01525 860000 www.english-heritage.org.uk/wrest

Osborne, Isle of Wight

A royal seaside escape

There is probably no better place in Britain to gain an insight into the lives of Queen Victoria and Prince Albert than Osborne. Designed by Albert in the 1840s, it became both a comfortable home and a place from where the queen worked. Here Victoria attended to state business, received dignitaries and ministers, and managed her family and staff. Imperial influences can be found in the decoration of the house, notably the Indian feel to the Durbar room. When Victoria wanted to escape the pressures of monarchy, she had a private beach nearby, with a bathing machine set on rails which allowed her to descend to the water, dignity intact. Following Queen Victoria’s death in 1901, some parts of the house were opened to visitors, while a naval college was also set up in the grounds. 01983 200022 www.english-heritage.org.uk/osborne

This article first appeared in the May 2013 issue of BBC History Magazine