In the last episode, Al-Khalili turns detective, hunting for clues that show how the scientific revolution that took place in the 16th and 17th centuries in Europe had its roots in the earlier world of medieval Islam. He travels across Iran, Syria and Egypt to discover the huge astronomical advances made by Islamic scholars through their obsession with accurate measurement and coherent and rigorous mathematics.He then visits Italy to see how those Islamic ideas permeated into the west and ultimately helped shape the works of the great European astronomer Copernicus, and investigates why science in the Islamic world appeared to go into decline after the 16th and 17th centuries, only for it to re-emerge in the present day. Al-Khalili ends his journey in the Royan Institute in the Iranian capital Tehran, looking at how science is now regarded in the Islamic world

In the fourth part of the series, Diarmaid MacCulloch makes sense of the Reformation, and of how a faith based on obedience and authority gave birth to one based on individual conscience. He shows how Martin Luther wrote hymns to teach people the message of the Bible, and how a tasty sausage became the rallying cry for Swiss Reformer Ulrich Zwingli to tear down statues of saints, allow married clergy and deny that communion bread and wine were the body and blood of Christ.

The film is the inside track on the World's most influential weapon. For over a thousand years this weapon dominated the battlefields of Japan, instilled fear and terror into every enemy it faced, and created a new spiritual way of life that lasts through to the present day. The Samurai sword – a weapon so technologically perfect in structure, so formidable in strength and so beautiful in creation. For the first time unique access has been granted and we travel into the core of the ancient foundries, sword-smiths and fighting schools to reveal what makes the so-called perfect sword. This is a no holds barred look at one of the most iconic man-made objects ever forged.

One hundred years after Columbus' arrival in the Caribbean, Spanish Conquistadors and Priests, push into North America in search of gold and to spread Catholicism. With the arrival of the British in North America, the two colonial systems produce contrasting societies that come in conflict as Manifest Destiny pushes the U.S into the Mexican territories of the South West. As the Gold Rush floods California with settlers, complex and vital communities are overwhelmed. The elites, including Mariano Vallejo and Apolinaria Lorenzana lose their land. Mexicans and Mexican Americans are treated as second-class citizens, facing discrimination and racial violence. Resistance to this injustice appears in New Mexico as Las Gorras Blancas (The White Caps), burn Anglo ranches and cut through barbed wire to prevent Anglo encroachment. At the same time, New Mexicans manage to transform themselves through education, managing to preserve Hispano culture in New Mexico and their standing in the midst of an era of conquest and dispossession.

Andrew Graham-Dixon reveals how the Medici family transformed Florence through sculpture, painting and architecture and created a world where masterpieces fetch millions today. Without the money and patronage of the Medici we might never have heard of artists such as Donatello, Michelangelo or Botticelli, and Graham-Dixon examines how a family of shadowy, corrupt businessmen, driven by greed and ambition, became the financial engine behind the Italian Renaissance.

Fancisco Pizarro hoped to find great riches in the land of the Inca when he set off on his third voyage to the new world in 1527. Travel back in time with Michael Wood and learn how Pizarro ransomed the life of a king for a room full of gold and silver. Trough letter and drawings from the 16th century and film from modern-day south America, discover this remarkable story of greed, faith, dishonor and valor.