Neil MacGregor's world history as told through objects at the British Museum. This week he is exploring high status objects from across the world around 700 years ago. Today he has chosen an astronomical instrument that could perform multiple tasks in the medieval age, from working out the time to preparing horoscopes. It is called an astrolabe and originates from Spain at a time when Christianity, Islam and Judaism coexisted and collaborated with relative ease - indeed this instrument carries symbols recognisable to all three religions. Neil considers who it was made for and how it was used. The astrolabe's curator, Silke Ackermann, describes the device and its markings, while the historian Sir John Elliott discusses the political and religious climate of 14th century Spain. Was it as tolerant as it seems?Producer: Anthony Denselow