Ask students around the world, and they will tell you why the British flag looks the way it does. It is a combination of the flags of three of the nations making up the United Kingdom: England, Scotland and Northern Ireland. 

That might give the impression that these nations just merged harmoniously into one. But the reality is quite different. The United Kingdom was built by conquest and double-dealing. Ireland and Wales were both invaded and Scotland agreed to unite with England because it was bankrupt.

So scratch the surface, and the history of the United Kingdom is not one of harmony and cooperation at all. At least, that is what Union, a new TV series by public historian David Olusoga, is trying to persuade people.

Olusoga says his aim is to teach people British history in a way that makes them feel uncomfortable. History, he insists, is not there to make us feel happy or special.

His supporters think that is an important message at a time when the way we think about our history is getting ever more divisiveCausing people to be split into groups that disagree with or oppose each other..

Last year the US state of FloridaA coastal state in the south-east of the US, between the Atlantic Ocean and the Gulf of Mexico. Though nicknamed "the sunshine state", it also experiences phenomenal rainstorms. passed a new law that bans schools from making people feel "discomfort" or "guilt" based on their background. Although it does not specify, most people think it is really aimed at preventing schools from teaching students about the history of racism. 

Olusoga was born in Lagos in 1970 to a White British mother and a Nigerian father. He moved to Gateshead, his mother's hometown, when he was a child. 

The family experienced racism from the far rightA range of ideologies that emphasise social order, racial purity, and the elimination of opponents. - a brick was thrown through their window, and they had to be rehoused. He went on to study history at the University of Liverpool, and then did a master's degreeAn advanced. academic degree. Master's degrees are taken by people who have already got one degree from a university. . 

He was proud of his Nigerian YorubaA language mainly spoken in southwestern Nigeria and Benin. heritage, and of his mother's White working class GeordiePeople from Tyneside/Newcastle in North East England. background. But he also knew he had a third identity: Black British. "That had no history, no recognition" he recalls. 

As an adult, and by now a renowned historian and presenter, he decided to tell the story of that history himself. In 2016, he published Black and British: A Forgotten History, which was then made into a TV series. It goes back as far as the first meeting of the people of Britain and the people of Africa in Roman times, discusses Britain's role in the slave trade and Olusoga's own childhood.

Yes: Any truthful account of history will tell that it is full of conflict and brutality. We have to face up to that because it is what has made the modern world an unjust place.

No: The more we tell ourselves that our history is full of bloodshed and savagery, the less we will trust each other in the present. It is better to focus on the things that unite us.

Or... The problem is that we believe we are defined by our history. Saying our history is full of cruelty feels tantamount to saying that we are too. We should break with our past and define ourselves by the present.

Divisive - Causing people to be split into groups that disagree with or oppose each other.

Florida - A coastal state in the south-east of the US, between the Atlantic Ocean and the Gulf of Mexico. Though nicknamed "the sunshine state", it also experiences phenomenal rainstorms.

Far right - A range of ideologies that emphasise social order, racial purity, and the elimination of opponents.

Master's degree - An advanced. academic degree. Master's degrees are taken by people who have already got one degree from a university.

Yoruba - A language mainly spoken in southwestern Nigeria and Benin.

Geordie - People from Tyneside/Newcastle in North East England.