In a turbulent era, the media must define its values and principles, writes Guardian editor-in-chief Katharine Viner

‘No former period, in the history of our Country, has been marked by the unrest of questions of a more important character than those which are now claiming the attention of the public .” So began the announcement, nearly 200 years ago, of a brand-new newspaper to be published in Manchester, England, which proclaimed that” the spirited discussion of political questions” and” the accurate detail of facts” were” particularly important at this crossroad “.

Now we are living through another extraordinary period in history: one defined by amazing political shocks and the disruptive impact of new technologies in every part of our lives. The populace sphere has changed more radically in the past two decades than in the previous two centuries- and news organisations, including this one, have worked hard to adjust.

But the turbulence of our time may demand that we do more than adapt. The circumstances in which we report, create, distribute and obtain the news have changed so dramatically that this moment requires nothing less than a serious consideration of what we do and why we do it.

The Scott Trust, which owns the Guardian, stated a very clear purpose when it was established in 1936:” to secure the financial and editorial independence of the Guardian in perpetuity and to safeguard the journalistic freedom and liberal values of the Guardian free from commercial or political interference .” As an editor, it's hard to imagine a finer mission for a proprietor: our sole shareholder is committed only to our journalistic freedom and longterm survival.

But if the mission of the Scott Trust is to ensure that Guardian journalism will exist for ever, it is still left to us to define what the mission of that journalism will be. What is the meaning and purpose of our run? What role do we play in society?

After working at the Guardian for two decades, I feel I know instinctively why it exists. Most of our journalists and our readers do, too – it's something to do with holding power to account, and upholding liberal values. We know what defines a Guardian tale, what feels like a Guardian perspective, what constructs something” very Guardian”( for better and for worse ).

In my own run as editor of the Guardian in Australia, and then as the editor of the Guardian in the US, I tried to conceptualise the Guardian with a different accent- to identify the essential qualities of Guardian journalism and bring them to new audiences. Now, as the editor-in-chief of the Guardian and the Observer, I believe our time necessitates something deeper. It is more urgent than ever to ask: who are now we, basically?

The answer to this question is in our past, our present and our future. I want to lead a Guardian that relates to the world in such a way that reflects our history, engages profoundly with this disorientating global moment, and is sustainable for ever.

The history of the Guardian begins on 16 August 1819, when John Edward Taylor, a 28 -year-old English journalist, attended an enormous demo for parliamentary reform in Manchester. In St Peter's Field, a popular radical speaker, Henry Hunt, addressed a crowd estimated to contain 60,000 people- more than half the population of the Manchester area at the time, dressed in their Sunday best and packed in so tightly that their hats were said to be touching.

At the time, the mood in the country was insurrectionary. The French revolution, three decades earlier, had spread throughout the world the seismic notion that ordinary people could face down the powerful and win- a revelation for the masses and a fright for those in power. After Britain's victory at Waterloo and the end of the Napoleonic wars, the country was mired in economic depression and high unemployment, while the Corn Laws, which maintained the price of grain artificially high, brought mass thirst. There were protests and riots throughout the country, from handloom weavers trashing freshly fabricated mill machinery to anti-slavery campaigners boycotting sugar.

There was also a growing campaign for the vote: the big, densely populated city of Manchester had no member of parliament- while Old Sarum, a prosperous hamlet in southern England, with simply one voter, had two MPs to represent him. The city's businessmen were demanding an overhaul of this rotten system- and running men( and, for the first time, females) wanted their own chance to vote.

The combination of economic depression, political repression and the politicisation of workers with economic need was combustible. As the essayist William Hazlitt wrote one year earlier,” nothing that was established was to be tolerated … the world was to be turned topsy-turvy .”

The Peterloo massacre of 1819. Photograph: Politenes of Manchester Libraries, Information and Archives

As most of Manchester gathered in St Peter's Field on 16 August, the city's magistrates, intimidated by the size of the crowd and their demands, ordered armed cavalry to charge into the crowd- to break up the session and apprehend Hunt and other speakers on the rostrum. The troops stormed through the person or persons, hacking with their sabres and” trim at everyone they could reaching “. Eleven people were killed on the day, seven men and four women, and many hundreds were injured. It became known as the Peterloo massacre or the Battle of Peterloo, and its impact was huge: the historian AJP Taylor used to say Peterloo” began the breakup of the old order in England “.

John Edward Taylor was in the crowd that day, reporting for a weekly paper, the Manchester Gazette. When a reporter for the daily Times of London was arrested, Taylor was concerned that the person or persons of the capital might not get an accurate report of the massacre- he correctly feared that without the account of a journalist on the scene, Londoners would instead get only the official version of events, which would protect the magistrates who had caused the bloodshed.

So Taylor rushed a report on to the night coach-and-four to London, got it into the Times, and thus turned a Manchester demonstration into their own nationals scandal. Taylor exposed the facts, without hysteria. By reporting what he had witnessed, he told the stories of the powerless, and held the powerful to account.

But Taylor did not be brought to an end. After the massacre, he spent months reporting on the fate of the wounded, documenting the injuries of more than 400 survivors.

Quick Guide

What was the Peterloo massacre?

What was the Peterloo massacre?

On 16 August 1819, a crowd of more than 50,000 gathered at St Peter's Fields outside Manchester to demand the reform of parliamentary representation.

Magistrates ordered the Manchester Yeomanry to scatter the demo and the sabre-wielding cavalry charged the crowd. At least 15 people died and up to 700 were injured.

Labelled Peterloo as an ironic nod to the battle of Waterloo, which had occurred four years earlier, the carnage triggered an outcry that was a key contributing factor in the process of creating the Manchester Guardian.

John Edward Taylor, a radical Quaker cotton merchant who did unpaid journalism for the Manchester Gazette, was at St Peter's Field on the day of the slaughter.

When the reporter from the London Times was arrested, Taylor and a friend sent an account of the killed to the paper to make sure the truth wasn't smothered by the official version. This was published along with an angry editorial based on the reporting.

Peterloo and its aftermath is proving to Taylor that reformers in Manchester needed their own voice. Two year later, and with the financial backing of 11 advocates, a prospectus for a new newspaper, the Manchester Guardian, was issued, stating:” It will zealously enforce the principles of civil and religion Liberty … It will warmly advocate the cause of Reform .” The first edition of the paper was published on 5 May 1821.

Photograph: Rischgitz/ Hulton Archive

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