After ending 120 years of civil war and reunifying Japan under his banner, Toyotomi Hideyoshi, the supreme ruler of Japan, lays dead. In a desperate attempt to protect his dynasty, just before his death, Hideyoshi created a council of five powerful warlords. They are to govern Japan until his young son comes of age. But the power hungry Tokugawa Ieasyu declares war on those who oppose him.

Brian asks how, from a lifeless cosmos, it is possible that a planet can produce the more than eight million species we know of.

This second instalment looks at how Vladimir Putin arrived in the Kremlin as a vulnerable and unknown president, whom the Russian oligarchs expect to control. The programme reveals how he asserted his hold on power and ultimately surrounded himself with his KGB peers, as well as his philosophy as regards traitors and enemies. The film also examines the stories of businessman Boris Berezovsky and defector Alexander Litvinenko, who both stood up to Putin and wound up dead on British soil.

In the third episode of the series, Commodus rises to power as Rome's new emperor, but not everyone supports his ascent. Among those conspiring against him: his older sister Lucilla.

Here, Aleks charts how the Web is forging a new brand of politics, both in democracies and authoritarian regimes. With contributions from Al Gore, Martha Lane Fox, Stephen Fry and Bill Gates, Aleks explores how interactive, unmediated sites like Twitter and YouTube have encouraged direct action and politicised young people in unprecedented numbers. Yet, at the same time, the Web's openness enables hardline states to spy and censor, and extremists to threaten with networks of hate and crippling cyber attacks.

Over the last years, the world has experienced an energy revolution, driven by an urgent need to green the grid and save life on Earth as we know it. 50 years ago, a devastating oil crisis kicked off an energy revolution. The world set course to cut the costly habit of burning fossil fuels. With the urgent new threat of a changing climate, the drive to unleash the power of the sun, earth and wind has accelerated into a race for humanity's survival. Change is taken place but, is it happening fast enough to secure our future? Technologies are right here, right now, and they will enable the transition to 100% renewables, because winning the energy race means a win for the entire world.