The author of the Campaigns of Alexander writes during the second century AD, about four hundred years after the fact. Arrian's full name is Lucius Flavius Arrianus, aka Xenophon, and he comes from a wealthy Greek family. He is a recognized historical authority on the life and times of Alexander the Great (July 20, 356-June 10, 323 BC). Aubrey de Selincourt translates the book and J.R. Hamilton adds footnotes to clarify and point out certain disputable facts, largely having to do with the names of places, geography and the numbers of troops involved in the battles.

Alexander begins his campaigns after the assassination of his father and he gains the throne of Macedonia. At twenty years of age, Alexander enlists as many Greeks as he can for his first set of adventures, quelling all opposition to him before making his way to Asia.

While in Asia, Alexander conquers city after city, fortress after fortress. He defeats the main Persian army in a battle famous for his tactical brilliance. In Egypt he is crowned a Pharaoh, which leads to Alexander's delusions of grandeur. He considers himself a god, which is against the ancient religion of the Greeks. Despite this flaw, Alexander founds Alexandria in Egypt, which is still a thriving and vibrant city.

Extending his empire as far as he can, Alexander takes on India. There he meets significant resistance, but he prevails on every challenge. Three mountain strongholds considered unconquerable fall to the Macedonians. However, Alexander's troops grow weary of the constant movement and fighting. They ask to go home, and Alexander capitulates when the signs from the gods turn out negative.

Alexander sails a massive flotilla down the Indus River to the Indian Ocean. He then marches across a terrible desert that results in many deaths along the way. Finally back in his empire, Alexander explores and tries to govern his empire. He takes to drinking heavily, and due to a fever, dies in Babylon. Speculation exists that he may have been poisoned.

The lands that Alexander conquers extend from the northern part of Greece to modern Turkey, Egypt, Iraq, Iran, Afghanistan, parts of Africa and India. No other military leader had ever accomplished as much, and for this reason alone Alexander is remembered. However, he did try to spread Greek culture throughout the world as well and is also remembered for this. The historian Arrian concentrates on the military aspect, and he is the first author in history to do this. Arrian's work is considered highly accurate from the military perspective.