Tropical medicine boomed as European powers claimed territories in Africa. Germany sent the famed Robert Koch and many others to the colonies to find cures to tropical illnesses - but also to test new medicines. This shadowy practice led to Africans being mistreated, and many died in the process, leaving a legacy of physical and psychological trauma that has never been properly cured.

Respected German anthropologists made a career from dividing people by race, a new branch of science that conveniently put Europeans at the top. While eugenics and scientific racism was widely practiced in Western nations in the early 1900s, the ideas developed by Eugen Fischer and others served as the intellectual bedrock for race-based crimes committed by Nazi Germany.

Why does Namibia have a bizarre panhandle? Why do some Ghanaians talk of being from "Western Togoland"? Much of this has to do with African borders drawn up in Europe during late 19th century. Borders that to this day are still very much contested, and have had deadly consequences. We explore how treaties designed to prevent war in Europe have caused conflict in Africa.

After the decisive Battle of Waterberg between German and Herero fighters, colonial officers in the colony of South West Africa, today's Namibia, directed a violent, uncompromising persecution of Herero and Nama people. Their policies would result in the 20th century's first genocide.

In July 1884, the imperial German flag was raised for the first time on the African continent - not in Tanzania or Namibia, but in Togo. The tiny protectorate became Togoland, and because Germany's 30-year rule seemed relatively peaceful compared to other German imperial conquests, Togoland was promoted as "a model colony". But it was a self-serving myth for German colonial administrators.

In East Africa and the Great Lakes region, German colonial conquest spurred courageous resistance from many local East African groups against well-armed and violent colonial forces.

European colonial rule across Africa lasted over 70 years. During this time, communities were not only physically uprooted, resettled, or changed forever, but their identity was, at best, ignored, and in many cases destroyed. In the grand scheme of colonial rule, renaming areas seems fairly mild. But it wasn't: it was in fact the colonialists' final stamp in making African lands their own.

Summer 1896: A Cameroonian man appeared in Treptower Park, Berlin as part of a human exhibition to increase enthusiasm for German colonialism. Little did anyone know this man — Martin Dibobe — would later become a pioneering human rights activist.

Adolph Woermann's company went from being a shipping firm to an unofficial instrument of German colonization. We explore how a Hamburg merchant grew rich in West Africa and transported the troops that subjugated the OvaHerero and Nama people.

By 1885, Adolf Lüderitz had acquired vast territories in today's Namibia. But his contracts with local people were so dodgy that even German colonial officials doubted them.

For our last episode of African Roots, we profile two giants: Mozambique's Eduardo Mondlane and South Africa's Nelson Mandela. We look at how the two men shaped their respective nations' trajectories in different eras, and how their fight against oppression inspired thousands of young people to take up the armed struggle.

Cai finds out how the legendary warriors, the Dahomey Amazons, have recently gained recognition - to dazzling Hollywood effects. But not all women fought on the battlefield: Laila explores how in neighboring in Nigeria, Margaret Ekpo blazed a trail for female participation in local politics as independence took hold.

Oral histories are key to shaping nationalities, legends and identities. Cai and Laila explore the role of West African griots in keeping alive the phenomenal stories of Sunjata Keita from Mali and Nigeria's Bayajida.

The relentless march of time changes histories and, sometimes, tarnishes reputation. Cai and Laila meet two nation builders, Usman Dan Fodio, and Liberia's William Tubman, whose legacies are perceived very differently today than during their lifetimes.

The role of women in Africa's liberation movements is underrepresented. African Roots meets Josina Machel, a freedom fighter whose efforts reshaped Mozambique's liberation movement in exile, and Bibi Titi Mohammed, who arguably won the grassroots support that drove Julius Nyerere to power in Tanzania.

History often leaves many vital figures out, and only after a few years does their absence stand out. We meet two anti-colonial fighters, Dedan Kimathi and Ngungunyane, and find out why their legacies were left to fade, and why great efforts have been made to remember them.

Ethiopia's Taytu Betul and Angola's Queen Njinga live large in their countries' historical memory as strong female leaders, and both embody the complicated power dynamics of their times. Just how did Taytu Betul help face down a European invasion? And why were Portuguese colonialists forced to talk with Queen Njinga on equal terms? Cai and Laila bring you their remarkable stories.

Arguably Africa's most influential revolutionary thinker, Amilcar Cabral, never saw his country gain independence. In the 1950s, Louis Rwagasore, briefly, seemed to unite a divided Burundi, but his time was cut short. We find out the tragic fates of these visionary leaders and how their ideas spread beyond their respective nations.

Every generation throws up a maverick - and Africa has had many! Laila introduces Cai to Wangari Maathai, who rewrote the rules for environmentalism in east Africa, and faced down stiff resistance in the process. Cai looks back to Cameroon's colonial era leader Njoya Ibrahim, a man of many talents who could have been anything - but, above all, achieved the status of an African hero.

Season 2 of the African Roots podcast is here! And we start off with two West African icons: Queen Amina of Zazzau and Queen Abla Pokou. Both women are nation builders of almost mythical proportions, so hosts Cai and Laila delve into why these two royals went on to drastically change their society's fate.

What was it like living under the tyranny of slavery? Cai and Laila open a cruel chapter of human history by meeting two figures who felt the consequences of the Transatlantic slave trade very differently: Sengbe Pieh, hero of the Amistad court case, and Afonso the First, whose Kongo Kingdom was decimated by slave raids.

Fatima al-Fihiri's legacy as a supporter of education hold immeasurable cultural and educational value, still being felt today. Meanwhile, further south into the Sahara, Ahmed Baba's teachings became a landmark for Muslims across Africa. Listen to their stories right here on the African Roots podcast!

When the men stood down, the women stood firm. Cai and Laila meet the fearsome warrior Princess Yennenga, whose famous stallion has become a symbol of Burkina Faso. Meanwhile, Yaa Asantewaa caused such problems for British colonialists that an entire war was named after her.

When the winds of freedom from colonialism swept across Africa in the 1960s, new nations were tasked to develop into functioning democracies overnight - most without success. Cai and Laila profile two giants of the African independence era - who took radically different, but in some ways similar, paths.