Do you like cocoa? You are in good company: in South and Central America people have been enjoying the fruit of the cacao tree - the source of cocoa, chocolate and much else - for thousands of years. Ancient empires fought battles for the control of the best trees, cacao beans were used as currency, and being able to make a tasty cacao drink could even save your life. To trace the history of cacao in Latin America, Bridget Kendall is joined by archaeologist Cameron McNeil, chef and food historian Maricel Presilla and geneticist and cacao researcher Juan Carlos Motamayor. The reader is Joseph Balderama.

(Photo: A cropped cocoa pod lies over dried cacao beans. Credit: Getty Images)

The Hoover Dam in the US, the Aswan Dam in Egypt and the recently opened, and sumptuously named, Grand Ethiopian Renaissance dam. Since modern times, huge mega dams like these to tame rivers, create water storage and hydropower, have become a symbol of nationhood used to create national pride and bolster political power, from the Cold War to today. Nehru, the first Prime Minister of India, called dams the temples of modern India. But dams have also been highly controversial, displacing rural populations, disrupting local ecology and more recently it’s been shown that dams can increase the amount of greenhouse gases in the earth’s atmosphere. So why are so many countries like China still highly involved in dam building, and will they need to change tack in the future? And, could the humble beaver offer a solution?

To discuss the past, present, and future of dam building, Rajan Datar is joined by Nikita Sud, Professor of the Politics of Development at Oxford University; Donald C. Jackson the Cornelia F. Hugel Professor of History at La Fayette University in the US and author of many books on the history of dam building, including Building the Ultimate Dam: John S. Eastwood and the Control of Water in the West; and Dr Majed Akhter, a political geographer who is senior lecturer in Geography at King’s College London. With the contribution of Dr Emily Fairfax, an ecohydrologist with an expertise in beaver activity and beaver dams from California State university Channel Islands in the US.

Produced by Anne Khazam for the BBC World Service.

(Photo: The Hoover Dam on the Colorado River straddling Nevada and Arizona at dawn. Credit: Sean Pavone via Getty Images)

From Persia to India to Greece – they called him The Great – that is Alexander the Great. Also known as Alexander III of Macedon, he was one of the most successful military leaders of all time. Undefeated by the time of his death in 323 BCE, he is still a go-to figure when people want to define an empire builder. But how should we view this often cruel and destructive militarist today in the light of current world events? And, despite his brutality, like his ransacking of the beautiful capital city of Persepolis, is there a more progressive side to Alexander, his desire for cultural assimilation for instance, that explains why he became an inspiration not just to nationalists and imperialists but also to writers, poets, and the gay community?

To discuss the relevance of Alexander the Great today, Rana Mitter is joined by James Romm, Professor of Classics at Bard College in New York state whose latest book is Demetrius: Sacker of Cities, the failed but would-be successor to Alexander the Great; Dr Haila Manteghi from the University of Münster in Germany who’s the author of Alexander the Great in the Persian tradition; Ali Ansari, Professor of Iranian History at the University of St Andrews in the UK; and Meg Finlayson, a specialist on the evolution of the queer Alexander, from the University of Durham in the UK.

Produced by Anne Khazam for the BBC World Service.

(Photo: The Alexander mosaic, a Roman floor mosaic from Pompei that dates from circa 100 BCE. Credit: Simone Crespiatico via Getty images)

From coronations to cup finals, many of us love a big event, a ceremony with age-old observances. Indeed rituals, whether public spectaculars or more personal ones, such as a particular daily routine, have been part of human experience since time began. But why do rituals persist even though so many of them seem to serve no obvious practical purpose?

(Photo: Shinto priests conduct the Oharae ritual in Tokyo. Credit: Tomohiro Ohsumi/Getty Images)

Drawing on traditional music, pop culture, kitsch, rock and modernist poetry to mention just a few of their sources of inspiration, the short-lived Tropicália movement in late 1960s Brazil was provocative and anti-authoritarian. Perhaps most importantly it represented a uniquely Brazilian aesthetic that could only have emerged from that country’s specific culture and history.

The movement’s leading lights were eventually arrested by the military regime that governed Brazil at the time, and exiled to London. But Tropicália paved the way for other performers to demand artistic freedom.

With the help of musical examples, Rajan Datar and guests will explore what made Tropicália so disruptive.

(Image: Gilberto Gil in The Unique Concert at The Reunion in France. Credit: IMAZ PRESS/Gamma-Rapho via Getty Images)

Nearly everything we consume is transported by ship. The biggest container ships in the world are among the largest moving structures made by man and can carry over 24,000 20-foot container units. The standardisation of these simple metal containers in the 1950s and 60s marked a turning point in world trade, driving down costs and ultimately fuelling globalisation. Now that supply chains have become ever more complex and been put under increasing strain, we take a look at the history of the shipping container.

Joining Rajan Datar are Marc Levinson, American historian and economist and author of The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger; Alan McKinnon, professor of Logistics at Kühne Logistics University in Hamburg and author of Decarbonising Logistics: Distributing Goods in a Low Carbon World; Yash Gupta, shipping industry expert with over 20 years’ experience in vessel management and logistics.

Presenter: Rajan Datar

(Photo: Aerial view of a container ship passing under a suspension bridge with truck crossing above. Credit: Shaul/Getty Images)

Developments in new technology such as DNA sequencing have transformed our understanding of the Neanderthals, one of a group of archaic humans who occupied Europe, the Middle East and Western Asia more than 300,000 years ago.

First identified by fossil remains in 1856 in a German quarry, the Neanderthals led an extremely physical existence as hunter-gatherers. They were stronger than us, adaptable as a species to huge variations in climate, with brains as large as ours and sophisticated ways of creating tools.

Many of us carry some of the DNA of Neanderthals, thanks to interbreeding with homo sapiens. Although the Neanderthals today are no longer with us, their story has a lot to tell us about ourselves and our future survival on the planet.

Rajan Datar is joined by Janet Kelso, a computational biologist and Group Leader of the Minerva Research Group for Bioinformatics at the Max Planck Institute for Evolutionary Anthropology. She specialises in the analysis of DNA sequencing of ancient people such as Neanderthals; Katerina Harvati, the Senckenberg Professor for Paleoanthropology and Director of the Institute for Archaeological Sciences at the University of Tübingen. Her work focuses on the origins of modern humans and Neanderthal evolution; and archaeologist and writer Rebecca Wragg Sykes, Honorary Fellow in the School of Archaeology, Classics and Egyptology at the University of Liverpool. Her award-winning book Kindred: Neanderthal Life, Love, Death and Art was published in 2020.

Produced by Fiona Clampin for the BBC World Service

(Image: Neanderthal Female, re-created by artists Andrie and Alfons Kennis. Photo: Joe McNally/Getty Images)

A Russian army stands at the gates of the capital of another country, a country that Russia has previously occupied and one that, according to Russian politicians, has no right to independent existence. Sounds familiar? That capital city was Warsaw and the year was 1920. But what happened in Poland just after the end of World War One bears strong similarities to what went on near Kyiv in 2022.

After the First World War, Russian Bolsheviks, and Lenin in particular, wanted to reoccupy Poland, and indeed Ukraine, Belarus and some other countries, so that they could serve as a bridge for exporting communist revolution to Western Europe. The Poles resisted even though at first they were outnumbered and outgunned by the Russians. The result was the Polish-Bolshevik war which was not fully resolved until 1921 and which had a big impact on the future shape of inter-war Europe.

To guide us through the Polish-Bolshevik war are three distinguished historians: Dr. Pawel Duber, researcher at Nottingham Trent University whose work focuses on Poland in the first half of the 20th Century; Anita Prazmowska, professor of International History at London School of Economics and the author of many publications on Polish history in the last century and beyond; Robert Service, emeritus professor of Russian history at Oxford University, whose books cover Russia from the Mongol conquest to Putin.

(Photo: Red Army on the Polish front, c.1920. Credit: Photo 12/Getty Images)

The pandemic has made us all rethink how we work. Where once millions of people used to travel into work in tall glass buildings in big cities every day, now our idea of the office has come to include the kitchen table or maybe even a coffee shop. Yet despite the temptation to shift permanently to remote working, many organisations say the events of the past few years have actually underlined the importance of offices as spaces that connect people. So what are offices for? We are delving back into the history of the modern office to learn how past designs could help us in the future.

Presenter Rajan Datar is joined by three guest experts:

Nigel Oseland is an environmental psychologist and consultant at Workplace Unlimited in the UK. He's the author of Beyond the Workplace Zoo: Humanising the Office.

Jennifer Kaufmann-Buhler is Associate Professor of Design History at Purdue University in West Lafayette, Indiana. She's the author of Open Plan: A Design History of the American Office.

And Agustin Chevez is a workplace researcher and architect, and Adjunct Research Fellow at the Centre for Design Innovation at Swinburne University in Melbourne, Australia. He's the author of The Pilgrim's Guide to the Workplace.

Producer: Jo Impey

(Photo: Modern coworking interior with an open-plan office lounge and plants; Credit: ExperienceInteriors/Getty Images)

In the summer of 1946 inflation in Hungary reached 41.9 quadrillion per cent. That’s 41.9 followed by 14 zeros – the highest rate of inflation ever recorded anywhere in the world. It meant prices of everyday goods and services doubled, on average, every 15 hours.

As the shattered country struggled to get to its feet after World War Two, weighed down by a Soviet occupation and punishing reparations, its government had little choice but to print more and more money, further fuelling the price spiral.

The hyperinflation stripped wages of almost all their value and plunged millions of Hungarians into a new fight for survival, but as they lost all faith in banknotes they turned to ever more inventive ways to trade and earn a living. We discuss how life for ordinary Hungarians changed amidst the chaos, what caused and eventually halted the economic disaster, and what the whole episode can tell us about the meaning of money.

Bridget Kendall is joined by Béla Tomka, professor of modern social and economic history at the University of Szeged, in Hungary; László Borhi, the Peter A Kadas Chair and associate professor in the Department of Central Eurasian Studies in the Hamilton-Lugar School at Indiana University, USA; and Pierre Siklos, professor of economics at Wilfrid Laurier University in Waterloo, Canada.

Producer: Simon Tulett

(Picture: Hungarian pengo banknotes lying on the ground in Budapest. Credit: Louis Foucherand/AFP via Getty Images)