haruspex (pl. haruspices): a soothsayer. A man trained to divine in many ways, from the inspection of animal entrails to the shapes of clouds and the way birds fly. As the perceived source of blood, and therefore life itself, the liver was particularly valued for its divinatory possibilities. In addition, many natural phenomena – thunder, lightning, wind – could be used to interpret the present, past and future. The bronze liver mentioned in the book really exists; it was found in a field at Piacenza, Italy in 1877.

homa: the sacred liquid drunk by members of various eastern religions such as Jainism. It was common practice for devotees in ancient times to take hallucinogenic substances when worshipping their gods. With secret rituals and rites of passage, it is not unreasonable to think that those who practised Mithraicism did the same.

intervallum: the wide, flat area inside the walls of a Roman camp or fort. As well as serving to protect the barrack buildings from enemy missiles, it could when necessary allow the massing of troops before battle.

Juno: sister and wife of Jupiter, she was the goddess of marriage and women.

Jupiter: often referred to as ‘Optimus Maximus’ – ‘Greatest and Best’. Most powerful of the Roman gods, he was responsible for weather, especially storms. Jupiter was the brother as well as the husband of Juno.

lacerna (pl. lacernae): originally a military cloak, it was usually a dark colour. Made of dyed wool, it was lightweight, open-sided and had a hood.

lanista (pl. lanistae): a gladiator trainer, often the owner of a ludus, a gladiator school.

latifundium (pl. latifundia): a large estate, usually owned by Roman nobility, and which utilised large numbers of slaves as labour. The origin of the latifundium was during the second century BC, when vast areas of land were confiscated from Italian peoples defeated by Rome, such as the Samnites.

legate: the officer in command of a legion, and a man of senatorial rank. In the late Roman Republic, legates were still appointed by generals such as Caesar from the ranks of their family, friends and political allies.

liburnian: a faster and smaller ship than the trireme, the liburnian was adapted by the Romans from its origins with the Liburnian people of Illyricum (modern-day Croatia). With two banks of oars, it was a bireme rather than a trireme. It was powered by sail, by oars or by a combination of both.

licium: linen loincloth worn by nobles. It is likely that all classes wore a variant of this: unlike the Greeks, the Romans did not believe in unnecessary public nudity.

lictor (pl. lictores): a magistrates’ enforcer. Only strongly built citizens could apply for this job, essentially the bodyguards for the consuls, praetors and other senior Roman magistrates. Such officials were accompanied at all times in public by set numbers of lictores (the number depended on their rank). Each lictor carried a fasces, the symbol of justice: a bundle of rods enclosing an axe. Other duties included the arresting and punishment of wrongdoers.

ludus (pl. ludi): a gladiator school.

manica (pl. manicae): an arm guard used by gladiators. It was usually made of layered materials such as durable linen and leather, or metal.

mantar: a Turkish word meaning ‘mould’. I have taken advantage of its exotic sound to use it as a word for the penicillin powder that Tarquinius uses on Pacorus.

manumission: during the Republic, the act of freeing a slave was actually quite complex. It was usually done in one of three ways: by claim to the praetor, during the sacrifices of the five yearly lustrum, or by a testamentary clause. A slave could not be freed until at least the age of thirty and continued to owe some formal service to their former master after manumission. During the empire, the process was made much simpler. It became possible to grant manumission verbally at a feast, using the guests as witnesses.

Mars: the god of war. All spoils of war were consecrated to him, and no Roman commander would go on campaign without having visited the temple of Mars to ask for the god’s protection and blessing.

Minerva: the goddess of war and also of wisdom.

Mithraeum (pl. Mithraea): the underground temples built by devotees of Mithras. The internal layout described in the novel is accurate. Examples can be found from Rome (there is one in the basement of a church just five minutes’ walk from the Coliseum) to Hadrian’s Wall (Carrawburgh, among others).

Mithras: originally a Persian god, he was born on the winter solstice, in a cave. He wore a Phrygian blunt-peaked hat and was associated with the sun, hence the name Sol Invictus: ‘Unconquered Sun’. With the help of various creatures, he sacrificed a bull, which gave rise to life on earth – a creation myth. The sharing of wine and bread, as well as the shaking of hands were all possibly initially Mithraic rituals. Unfortunately we know little about the religion, except that there were various levels of devotion, with rites of passage being required between them. A mosaic in a Mithraeum at Ostia reveals fascinating snippets about the seven levels of initiate. With its tenets of courage, strength and endurance, Mithraicism was very popular among the Roman military, especially during the Empire. Latterly the secretive religion came into conflict with Christianity, and it was being actively suppressed by the fourth century AD.

mulsum: a drink made by mixing four parts wine and one part honey. It was commonly drunk before meals and with the lighter courses during them.

murmillo (pl. murmillones): one of the most familiar types of gladiator. The bronze, crested helmet was very distinctive, with a broad brim, a bulging face-plate and grillwork eyeholes. The crest was often fitted with groups of feathers, and may also have been fashioned in a fish shape. The murmillo wore a manica on the right arm and a greave on the left leg; like the legionary, he carried a heavy rectangular shield and was armed with a gladius. His only garments were the subligaria, an intricately folded linen undercloth, and the balteus, a wide, protective belt. In Republican times, the most common opponent for the murmillo was the secutor, although later on this became the retiarius.

olibanum: frankincense, an aromatic resin used in incense as well as perfume. Highly valued in ancient times, the best olibanum was reportedly grown in modern-day Oman, Yemen and Somalia. For obvious reasons, I have not used today’s name as it refers to the Franks who reintroduced it to Europe in the Middle Ages.

Optimates: an historical but informal faction in the Senate. Its members were dedicated to maintaining the honourable traditions and standards of the Roman Republic, while its main opponent, the Populares group, stood more for what the people wanted. At the time of The Silver Eagle, the most prominent member of the Optimates was Cato, who had been harbouring ill-feeling towards Caesar since 59 BC. Then a consul, Caesar had acted illegally by using physical force to further his cause. Damningly, he had also founded the triumvirate which took nearly all the power from the Senate and placed it in the hands of just three men. Then he had taken it upon himself to conquer Gaul, making himself incredibly wealthy. In the process, Caesar formed the largest and most battle-hardened army Rome had ever seen, one which was loyal only to him. Attempts by the Optimates to recall Caesar prematurely from Gaul were unsuccessful, but then a successful charge of corruption against Gabinius (see the final chapter, set in Alexandria), the acting governor of Syria, gave them heart. But without an army to back them up, the Optimates had little real power to force Caesar into a court. After making a deal with Pompey to restore the peace in 52 BC however, the faction saw a golden opportunity. Over the following months, they assiduously courted Pompey, the only man with the military might to help them. Ultimately, and against the initial wishes of the majority of the Senate, they were successful. Their actions, and Caesar’s refusal to stand down, precipitated the civil war.