The World

Now accompanying Marcus and Lucius as they travelled north towards the German war, Galen watched the army being annihilated by the plague, noting its symptoms. In this period, and during its second surge a few years later, its mortality rate was 25 per cent and it killed 2,000 a day in Rome, 250,000 in total. Rome never recovered, and Europe knew no more million-strong cities until 1800. Villages all over the empire were left empty, with as much as 10 per cent of the population killed, and the army was ravaged too, all of which created a labour shortage that may have affected the Roman ability to find troops to hold the German and Danube frontiers. The plague hit the Germanic tribes as well, but they did not live in cities and could move camp easily. Its effect in weakening the empire was as important as it is incalculable: pandemics are invisible and inexplicable, but they have brought down more empires than any number of demented emperors and fierce battles.

Marcus kept away from Rome, while Galen prescribed a special tonic of theriac, myrrh, snake flesh and, perhaps most usefully, opium poppy juice. On the way back home Lucius, just thirty-nine, contracted the plague and perished. Now Marcus concentrated on protecting his eight-year-old son Commodus, who was cared for by Galen.

In 169, Marcus launched his war against Germanic tribes, who resisted strongly, defeating at least one of his armies and invading both Italy and Greece. But the emperor, learning the military craft on the job, persisted, aided by miracles such as a lightning bolt that destroyed German siege engines and a freak rainstorm that rescued a beleaguered legion. At last defeating the Germans in battle, in 175 he negotiated a peace, allowing many Germans to settle within the empire and serve in the Roman army, including the horsewomen whose skeletons were found near Hadrian’s Wall in northern Britannia.

Marcus spent several years at the front, contemplating the meaning of existence.^* But absence from Rome was dangerous. A rumour spread that he was dead, reaching Faustina, whose priority was to safeguard the succession for Commodus. This false news was the first in a series of misunderstandings: Faustina wrote to Avidius Cassius, rector orientis, eastern viceroy, to get his backing if Marcus really was dead. Whether deliberately or not, Faustina had betrayed her husband.

THE PHILOSOPHER’S MONSTER: COMMODUS

A vicious martinet who claimed descent from Seleukos, Augustus and Herod – an ominous combination – Avidius declared himself emperor. But in the west Marcus was popular – and very much alive. A centurion beheaded Avidius and sent the head to Marcus, who just had it buried, refusing to take vengeance (‘May it never happen,’ he told senators, ‘that any of you should be killed either by my vote or by yours’), and he burned Avidius’ correspondence with his wife without reading it.

Somehow Marcus and Faustina reconciled, but soon afterwards, travelling with Marcus, Faustina died, aged forty-five. Marcus grieved for her – ‘such a fine woman, so obedient, so loving, so simple’ – but on his return from his eastern travels he promoted Commodus, just fifteen, to co-emperor and consul, the youngest ever. As Marcus returned to fight the Germans, Commodus was his companion, but the smirking hellion came to loathe his fastidious father. Marcus knew that Commodus was flawed, but fortunately parents are programmed to be deluded about their children. Many teenagers are spoiled, but imperial heirs were superlatively spoiled. ‘If you can, convert him by teaching; if not remember that kindliness was given to you for this very thing,’ Marcus suggested. ‘Kindliness is invincible,’ so he would say, ‘No, child, you are harming yourself, child.’ But he was faced with a simple but terrible dilemma understood only by autocrats: either he chose Commodus as heir and ensured a smooth succession, or he named someone else and had to kill his own son or condemn him to rebellion and death.