How should art depict the relationship between man and God? How can art best express eternal values? Can you and should you portray the face of Christ? For over 1,000 years these were some of the questions which taxed the minds of the greatest artists of the early West. In this three-part series, art historian Andrew Graham-Dixon sets out to unravel the mysteries of art from the pre-perspective era". In the first episode, Andrew traces the beginnings of Christian art in the declining Roman Empire, Egypt and medieval France, and reveals the ideas which lay behind the transition

Guernica (1937) was created during Picasso's Surrealist period and captures the horror of the bombing of the Basque town of Guernica during the Spanish Civil War. By the end of World War II, Picasso had become an internationally known artist and celebrity.

Hernan Cortes left Cuba in 1519 seeking riches in the island to the west. Instead he discovered, and ultimately destroyed, a hitherto unknown civilization. Join Micheal Wood as he retraces this fateful expedition. Read Spanish eyewitness accounts that describe the conquistadors' awe at the Aztec achievements and the lust for native treasure. Learn the Aztec' side of the story by scrolling trough pictographs that tell of the agonizing fall of the empire.

Audrey Hepburn was a film and fashion icon of the twentieth century and one of the most beloved actresses of all time. She enchanted the world with elegance and innocent charm, and portrayed some of the most memorable characters in film. Although she was one of the few actresses to win an Emmy, Tony, Grammy, and Academy Award, Audrey was modest about her talents, often claiming she had no acting technique. She redefined glamour with elfin features and a waif-like figure that inspired timeless designs by Hubert de Givenchy.Raised in the Netherlands during World War II, Audrey never forgot her own struggles during the German occupation and dedicated her later years to helping needy children around the world, becoming an International Goodwill Ambassador for UNICEF and traveling around the world to provide aid. Audrey Hepburn is remembered as a natural talent, a timeless beauty and a great humanitarian.

In 2014, the International Space Station had to move three times to avoid lethal chunks of space debris and there is an increasing problem of satellites mysteriously breaking down. With first-hand accounts from astronauts and experts, know the scale of the problem of space junk. Our planet is surrounded by hundreds of millions of pieces of junk moving at 17,000 miles per hour. Now the US government is investing a billion dollars to track them, and companies around the world are developing ways to clear up their mess - from robot arms to nets and harpoons. Learn the science behind the hit film Gravity and discovers the reality is far more worrying than the Hollywood fiction.

In this final episode we complete our journey, travelling back from the March equinox to the end of June. Kate Humble is in the Arctic at a place where spring arrives with a bang, whilst Helen Czerski chases a tornado to show how the earth's angle of tilt creates the most extreme weather on earth.