The following correction was printed in the Guardian's Corrections and clarifications column, Wednesday 10 June 2009

In the article below two dukes went wrong in a piece about the political power of walking. It was not the 8th Duke of Devonshire, but the 9th, who insisted on prosecuting ramblers who staged the "Kinder Scout trespass" on his land in 1932. Nor was it the 10th Duke of Norfolk who later apologised over the resulting jailings, but the 11th, as the Guardian reported in April 2002 when thousands gathered to celebrate the 70th anniversary of the march: "Suddenly the sea of Gore-Tex parted for a stooped and elderly figure wearing a long tweed coat and brown suede shoes ... Andrew Robert Buxton Cavendish, the 11th Duke of Devonshire and the biggest private landowner in the Peak District, had travelled from his stately home at Chatsworth to the village of Hayfield to make a public apology" for the actions of his grandfather.

Walking being, like the health service, free at the point of use, it has always attracted the working classes. Its philosophy, if it has one, is that the spirit is uplifted and the soul purified by a day of fresh air and healthy exertion - though some devotees think that a pint and a pie in a pub are essential ingredients of that ennobling experience. Walkers are more inclined to believe (with Blake) that the golden age is yet to come, than to fear (with Cobbett) that it is in the past. So "political walks", as you'll find on the following pages, are likely to have radical associations.

In 1892 William Gladstone opened a pathway through the foothills of Snowdonia, speaking "from a granite plateau with his silver locks blowing in the wind". The audience believed that the land belonged to the people. Thirty years later, David Lloyd George stopped as he walked the bank of the River Dwyfor and said: "Bury me here. Don't put me in the churchyard. You'll have trouble with the family."

Today, in Llanystumdwy, you can walk from the cobbler's cottage where he spent his boyhood along the same path. It passes the great boulder that marks the grave and goes through the woods that provided Lloyd George with some of his most colourful metaphors. Perhaps it has become more of a pilgrimage than a hike. That is how it is with political walks: most have been trod by heroes.

The heroes do not have to be familiar names. Walkers who follow in the Levellers' footsteps, for example, may have heard of the eloquent colonels Rainsborough and Lilburne. But in Putney, where a new English constitution was debated in 1647, or Burford, where three Leveller soldiers were executed in 1649, they are marching in step with "the hobnails, clouted shoes, the private soldiers, the leather and wooden aprons and the laborious and industrial people of England" who mutinied against Cromwell.

Some political walks are really marches, like the Burston Walk in Norfolk, held on the first Sunday in September (see page 20). It celebrates the longest strike in British history: 1914 to 1939. Its cause was as unusual as its length. The managers of the local church school sacked two teachers, Kitty and Tom Higdon, and the pupils "came out in support". They set up their own rival establishment, and for a quarter of a century Burston parents footed the bill. They march in Burston to celebrate solidarity, independence and the willingness to pay the price of freedom. But the real "political walk" is 320km to the north-west.

Bias of birth and habitation alone might cause me to award that accolade to Kinder Scout in Derbyshire. As a boy, it was my ambition to climb and cross this windswept peak. The gradient I could manage, but it was two tram journeys and a bus ride away from my side of Sheffield; so the ambition was only occasionally realised. Now that I live almost within sight, one of us - either me or my 16-year-old dog - leaves it to younger walkers.

The creation of the Peak District national park - Britain's first - almost 60 years ago, however, was a political event in itself. Its original purpose was to provide an opportunity for the citizens of Sheffield, Leeds and Manchester to escape from their dark satanic mills. And the walk across its highest point of the High Peak is political in its own right. It was there, on 24 April 1932, that the "Kinder Scout Trespass" first asserted the right to roam, on land that was part of the Duke of Devonshire's grouse moors.

The walk across Kinder is not easy, even on a summer's day, and in winter it can be hazardous. But it provides, as well as the most spectacular gritstone scenery, a chance to contemplate the way in which the world has moved on.

In 1932, the men and women who set out on the trespass knew that they were committing the unforgivable offence of disturbing birds that had to be protected so they could be shot later in the year. So they would be challenged by the 8th Duke of Devonshire's gamekeepers. And they must have expected that they would not be allowed to pass without a struggle. Fights did break out; the police were called. Four of the trespassers were arrested, prosecuted on the duke's insistence, and imprisoned. In the town of New Mills, the house in which they were held on remand has a proud memorial plaque on its walls.

But the story has an almost happy ending. In 2002, on the 70th anniversary of the trespass, the 10th Duke of Norfolk arrived, unexpectedly, at the end of the march. He had come to apologise for the "great wrong" done by his grandfather. And he added a word in favour of walkers and walking. In 50 years no intentional damage had ever been done to the old duke's home of Chatsworth House or its gardens. Walking is a great healer.

• Roy Hattersley walked route 3497 (The site of the mass trespass), a 15km hill scramble

• This article was amended on 9 June 2009. The original referred to limestone scenery rather than gritstone. This has been corrected.