This programme focuses on the most famous Roman of all - Caesar. Charming, savage, power-crazed, opportunistic and brilliant, he overthrew a 500-year-old Republic and began the age of the emperors.

The third episode is devoted to the ways in which plants reproduce. Pollen and a stigma are the two components needed for fertilisation. Most plants carry both these within their flowers and rely on animals to transport the pollen from one to the stigma of another. To do this, they attract their couriers with colour, scent and nectar. It isn't just birds that help pollination: some mammals and reptiles also do so. However, it is mostly insects that are recruited to carry out the task. To ensure that pollen is not wasted by being delivered to the wrong flower, some species of plant have developed exclusive relationships with their visitors, and the gentian and its attendant carpenter bees is one example. Since pollen can be expensive to produce in terms of calories, some plants, such as orchids, ration it by means of pollinia and a strategically placed landing platform. Other orchids offer no reward for pollination, but instead mislead their guests by mimicking their markings and aroma, thus enticing males to 'mate' with them (Pseudocopulation). The most extreme fertilisation method is one of imprisonment, and one plant that uses it is the dead horse arum. It is often found near gull colonies, and mimics the appearance and smell of rotting flesh. Blow-flies are attracted to it, and are forced to stay the night before being allowed to depart in the morning, laden with pollen. Finally, Attenborough introduces the world's largest inflorescence: that of the titan arum.

Since Caesar's days, Germanic warriors and Roman legionaries had often met in battle. Rome's power seemed invincible. But then, in the year 9 AD, the Germans mounted a rebellion.

The Roman army turns its attention to an island of rich resources, powerful tribes and druids, and advanced military equipment - Britain. This episode tells the story of the Celts' last stand against the Roman army - a revolt led by another great leader, the warrior queen Boudicca.

In 1901, a group of divers excavating an ancient Roman shipwreck near the island of Antikythera, off the southern coast of Greece, found a mysterious object - a lump of calcified stone that contained within it several gearwheels welded together after years under the sea. The 2,000-year-old object, no bigger than a modern laptop, is now regarded as the world's oldest computer, devised to predict solar eclipses and, according to recent findings, calculate the timing of the ancient Olympics. Following the efforts of an international team of scientists, the mysteries of the Antikythera Mechanism are uncovered, revealing surprising and awe-inspiring details of the object that continues to mystify

One of Britain's most celebrated artists, Turner showed exceptional artistic talent from an early age and entered the Royal Academy aged fourteen. His English landscapes made his name but there was a darker side to his paintings that was difficult for the critics to swallow, both in the increasingly informal use of paint and the subject matter that was critical of the romanticised vision of Britain in the late nineteenth century.