Very little is known about Themistocles' father. We do know that his name was actually Neocles, because archaeologists have unearthed dozens of ostrica bearing his name. He was probably born sometime around 550 BCE. Plutarch states that his family was part of the Leontis tribe, but that may have been after Cleisthenes' social reforms, which took place around 508 BCE. Neocles may also have been connected to the Lycomidae, because his son would later rebuild a temple of theirs after the Persians burned it down in 480 BCE.
Neocles and his parents probably belonged to the Attican middle class, known as the zeugitai. They were rich enough to participate in battles as foot soldiers(hoplite), but not enough to be part of the knights(hippeis). Growing up, Neocles was aware that he would have little say in the Athenian assembly. Only the pentacosiomedimni (nobles) and hippeis were allowed to hold the highest offices of the land. Instead he was expected to live out his days tilling the dry, stubborn soil on his tiny farm in the deme of Phrearrioi, far south of Athens. Sometimes he would march in the phalanx against Attica's pushy neighbors Megara and Thebes. He might have even had a say in local politics. But that was all.
As part of the middle class, Neocles was expected to marry a woman in his social bracket. It would be a deal between himself and his future father-in-law, a formal arrangement with little if nothing to do with love. It is romantic to think that Neocles balked at social convention and married a foreigner from either Caria or Thrace while on campaign or in the city. But it is also possible that Themistocles' mother may have been a servant in Neocles' household. Most Greeks had at least two or three slaves, and almost all were from outside of Greece.
Whether father and son were close is not clear. Some ancient authors claim that Neocles disinherited his unruly son at a young age. Others write that Themistocles named a son after his father, suggesting a strong bond. In either case, if Neocles was alive at the time of Salamis, he was most likely very proud of his son.
In my story Neocles is a handsome but somewhat dour character. He is stubborn but not ambitious. He has no love for intrigue and politics and would rather stay on his farm than make the long journey to Athens to have his voice heard on the Pynx. Dark-haired with olive skin, he is slight of build and small in stature. He loves his son but has a hard time connecting with him; Themistocles' outgoing personality baffles him.