Beyond the answers - interesting background to this quiz

A capital chosen for the middle of the country

Abuja became Nigeria's capital in 1991, replacing Lagos, which had grown crowded and was located on the coast. The new city was planned from scratch and placed near the geographic centre of the country, partly to ease tensions between Nigeria's different regions. Today it is home to the Aso Rock presidential complex and a rapidly growing population.

The world's most familiar painkiller

Aspirin's formula, C9H8O4, belongs to a compound called acetylsalicylic acid. Its pain-relieving ancestor, salicylic acid, occurs naturally in willow bark, which has been used for aches for centuries. In 1897 Felix Hoffmann, a chemist at Bayer, synthesised a more tolerable version, and aspirin went on to become one of the most widely used medicines in history.

A revolution with almost no bloodshed

The Glorious Revolution of 1688 saw James II of England removed from the throne and replaced by his daughter Mary and her husband William of Orange. It earned its flattering name because it was largely achieved without widespread fighting. Its lasting legacy was constitutional: the Bill of Rights of 1689 limited royal power and strengthened Parliament.

The river that shaped Baghdad

The Tigris runs through the heart of Baghdad, the Iraqi capital, and together with the Euphrates it defined ancient Mesopotamia - the "land between the rivers". Baghdad was founded on the Tigris in 762 as the capital of the Abbasid caliphate and became a centre of learning, trade and translation during the Islamic Golden Age.

Cervantes and his unlikely duo

Sancho Panza is the loyal, earthbound squire who accompanies Don Quixote, the deluded knight-errant of Miguel de Cervantes's novel, published in two parts in 1605 and 1615. Where Quixote sees giants, Sancho sees windmills, and their bickering friendship gives the book much of its warmth. Often called the first modern novel, it remains one of the most translated works of fiction.