Themistocles was an Athenian politician and general. He was one of a new breed of non-aristocratic politicians who rose to prominence in the early years of the Athenian democracy. As a politician, Themistocles was a populist, having the support of lower class Athenians, and generally being at odds with the Athenian nobility. Elected archon in 493 BC, he convinced the polis to increase the naval power of Athens, which would be a recurring theme in his political career. During the first Persian invasion of Greece, he fought at the Battle of Marathon, and was possibly one of the 10 Athenian strategoi in that battle.
In the years after Marathon, and in the run up to the second Persian invasion he became the most prominent politician in Athens. He continued to advocate a strong Athenian navy, and in 483 BC he persuaded the Athenians to build a fleet of 200 triremes; these would prove crucial in the forthcoming conflict with Persia. During the second invasion, he was in effective command of the Greek allied navy at the battles of Artemisium and Salamis. Due to subterfuge on the part of Themistocles, the Allies lured the Persian fleet into the Straits of Salamis, and the decisive Greek victory there was the turning point in the invasion, which was ended the following year by the defeat of the Persians at the land Battle of Plataea.