Melvyn Bragg and guests discuss the violent protests in China on 4th May 1919 over the nation's humiliation in the Versailles Treaty after World War One. China had supported the Allies, sending workers to dig trenches, and expected to regain the German colonies on its territory, but the Allies and China's leaders chose to give that land to Japan instead. To protestors, this was a travesty and reflected much that was wrong with China, with its corrupt leaders, division by warlords, weakness before Imperial Europe and outdated ideas and values. The movement around 4th May has since been seen as a watershed in China’s development in the 20th century, not least as some of those connected with the movement went on to found the Communist Party of China a few years later.The image above is of students from Peking University marching with banners during the May Fourth demonstrations in 1919.With Rana Mitter Professor of the History and Politics of Modern China and Fellow of St Cross College, University of OxfordElisabeth Forster Lecturer in Chinese History at the University of SouthamptonAnd Song-Chuan Chen Associate Professor in History at the University of WarwickProducer: Simon Tillotson

Melvyn Bragg and guests discuss the events of 21st October 1805, in which the British fleet led by Nelson destroyed a combined Franco-Spanish fleet in the Atlantic off the coast of Spain. Nelson's death that day was deeply mourned in Britain, and his example proved influential, and the battle was to help sever ties between Spain and its American empire. In France meanwhile, even before Nelson's body was interred at St Paul's, the setback at Trafalgar was overshadowed by Napoleon's decisive victory over Russia and Austria at Austerlitz, though Napoleon's search for his lost naval strength was to shape his plans for further conquests.The image above is from 'The Battle of Trafalgar' by JMW Turner (1824).WithJames Davey Lecturer in Naval and Maritime History at the University of ExeterMarianne Czisnik Independent researcher on Nelson and editor of his letters to Lady HamiltonAndKenneth Johnson Research Professor of National Security at Air University, AlabamaProducer: Simon Tillotson

Melvyn Bragg and guests discuss the republic that emerged from the union of the Kingdom of Poland and Grand Duchy of Lithuania in the 14th Century. At first this was a personal union, similar to that of James I and VI in Britain, but this was formalised in 1569 into a vast republic, stretching from the Baltic to the Black Sea. Kings and princes from across Europe would compete for parliament to elect them King and Grand Duke, and the greatest power lay with the parliaments. When the system worked well, the Commonwealth was a powerhouse, and it was their leader Jan Sobieski who relieved the siege of Vienna in 1683, defeating the Ottomans. Its neighbours exploited its parliament's need for unanimity, though, and this contributed to its downfall. Austria, Russia and Prussia divided its territory between them from 1772, before the new, smaller states only emerged in the 20th Century. The image above is Jan III Sobieski (1629-1696), King of Poland and Grand Duke of Lithuania, at the Battle of Vienna 1683, by Marcello Bacciarelli (1731-1818)With Robert Frost The Burnett Fletcher Chair of History at the University of AberdeenKatarzyna Kosior Lecturer in Early Modern History at Northumbria UniversityAndNorman Davies Professor Emeritus in History and Honorary Fellow of St Antony’s College, University of OxfordProducer: Simon Tillotson

Melvyn Bragg and guests discuss the race to build an atom bomb in the USA during World War Two. Before the war, scientists in Germany had discovered the potential of nuclear fission and scientists in Britain soon argued that this could be used to make an atom bomb, against which there could be no defence other than to own one. The fear among the Allies was that, with its head start, Germany might develop the bomb first and, unmatched, use it on its enemies. The USA took up the challenge in a huge engineering project led by General Groves and Robert Oppenheimer and, once the first bomb had been exploded at Los Alamos in July 1945, it appeared inevitable that the next ones would be used against Japan with devastating results.The image above is of Robert Oppenheimer and General Groves examining the remains of one the bases of the steel test tower, at the atomic bomb Trinity Test site, in September 1945.WithBruce Cameron Reed The Charles A. Dana Professor of Physics Emeritus at Alma College, MichiganCynthia Kelly Founder and President of the Atomic Heritage FoundationAndFrank Close Emeritus Professor of Theoretical Physics at the University of Oxford and a Fellow of Exeter College, OxfordProducer: Simon Tillotson

Melvyn Bragg and guests discuss the Greek writer known as the father of histories, dubbed by his detractors as the father of lies. Herodotus (c484 to 425 BC or later) was raised in Halicarnassus in modern Turkey when it was part of the Persian empire and, in the years after the Persian Wars, set about an inquiry into the deep background to those wars. He also aimed to preserve what he called the great and marvellous deeds of Greeks and non-Greeks, seeking out the best evidence for past events and presenting the range of evidence for readers to assess. Plutarch was to criticise Herodotus for using this to promote the least flattering accounts of his fellow Greeks, hence the 'father of lies', but the depth and breadth of his Histories have secured his reputation from his lifetime down to the present day.WithTom Harrison Professor of Ancient History at the University of St AndrewsEsther Eidinow Professor of Ancient History at the University of BristolAndPaul Cartledge A. G. Leventis Senior Research Fellow at Clare College, University of CambridgeProducer: Simon Tillotson

Melvyn Bragg and guests discuss the life and ideas of one of the great historians, best known for his History of the Decline and Fall of the Roman Empire (published 1776-89). According to Gibbon (1737-94) , the idea for this work came to him on 15th of October 1764 as he sat musing amidst the ruins of Rome, while barefooted friars were singing vespers in the Temple of Jupiter. Decline and Fall covers thirteen centuries and is an enormous intellectual undertaking and, on publication, it became a phenomenal success across Europe. The image above is of Edward Gibbon by Henry Walton, oil on mahogany panel, 1773.WithDavid Womersley The Thomas Wharton Professor of English Literature at St Catherine’s College, University of OxfordCharlotte Roberts Lecturer in English at University College LondonAnd Karen O’Brien Professor of English Literature at the University of OxfordProducer: Simon Tillotson

Melvyn Bragg and guests discuss Charles Booth's survey, The Life and Labour of the People in London, published in 17 volumes from 1889 to 1903. Booth (1840-1916), a Liverpudlian shipping line owner, surveyed every household in London to see if it was true, as claimed, that as many as a quarter lived in poverty. He found that it was closer to a third, and that many of these were either children with no means of support or older people no longer well enough to work. He went on to campaign for an old age pension, and broadened the impact of his findings by publishing enhanced Ordnance Survey maps with the streets coloured according to the wealth of those who lived there.The image above is of an organ grinder on a London street, circa 1893, with children dancing to the Pas de QuatreWithEmma Griffin Professor of Modern British History at the University of East AngliaSarah Wise Adjunct Professor at the University of CaliforniaAndLawrence Goldman Emeritus Fellow in History at St Peter’s College, University of OxfordProducer: Simon Tillotson

Melvyn Bragg and guests discuss the period between the execution of Charles I in 1649 and the unexpected restoration of his son Charles II in 1660, known as The Interregnum. It was marked in England by an elusive pursuit of stability, with serious consequences in Scotland and notorious ones in Ireland. When Parliament executed Charles it had also killed Scotland and Ireland’s king, without their consent; Scotland immediately declared Charles II king of Britain, and Ireland too favoured Charles. In the interests of political and financial security, Parliament's forces, led by Oliver Cromwell, soon invaded Ireland and then turned to defeating Scotland. However, the improvised power structures in England did not last and Oliver Cromwell's death in 1658 was followed by the threat of anarchy. In England, Charles II had some success in overturning the changes of the 1650s but there were lasting consequences for Scotland and the notorious changes in Ireland were entrenched.The Dutch image of Oliver Cromwell, above, was published by Joost Hartgers c1649With Clare Jackson Senior Tutor at Trinity Hall, University of CambridgeMicheál Ó Siochrú Professor in Modern History at Trinity College DublinAndLaura Stewart Professor in Early Modern History at the University of YorkProducer: Simon Tillotson

Melvyn Bragg and guests discuss the years of bloody conflict that saw Simon de Montfort (1205-65) become the most powerful man in England, with Henry III as his prisoner. With others, he had toppled Henry in 1258 in a secret, bloodless coup and established provisions for more parliaments with broader representation, for which he was later known as the Father of the House of Commons. When Henry III regained power in 1261, Simon de Montfort rallied forces for war, with victory at Lewes in 1264 and defeat and dismemberment in Evesham the year after. Although praised for supporting parliaments, he also earned a reputation for unleashing dark, violent forces in English politics and, infamously, his supporters murdered hundreds of Jewish people in London and elsewhere.With David Carpenter Professor of Medieval History at King’s College LondonLouise Wilkinson Professor of Medieval Studies at the University of LincolnAndSophie Thérèse Ambler Lecturer in Later Medieval British and European History at Lancaster UniversityProducer: Simon Tillotson

Melvyn Bragg and guests discuss the Roman poet Publius Ovidius Naso (43BC-17/18AD) who, as he described it, was destroyed by 'carmen et error', a poem and a mistake. His works have been preserved in greater number than any of the poets of his age, even Virgil, and have been among the most influential. The versions of many of the Greek and Roman myths we know today were his work, as told in his epic Metamorphoses and, together with his works on Love and the Art of Love, have inspired and disturbed readers from the time they were created. Despite being the most prominent poet in Augustan Rome at the time, he was exiled from Rome to Tomis on the Black Sea Coast where he remained until he died. It is thought that the 'carmen' that led to his exile was the Art of Love, Ars Amatoria, supposedly scandalising Augustus, but the 'error' was not disclosed.With Maria Wyke Professor of Latin at University College LondonGail Trimble Brown Fellow and Tutor in Classics at Trinity College at the University of OxfordAnd Dunstan Lowe Senior Lecturer in Latin Literature at the University of KentProducer: Simon Tillotson