Hey there! I can talk a bit about the movies portrayal of Artemisia.

Like most of the 300 movies, a lot of the events and people are sometimes based in Herodotus' Histories, which remain our main source on the Persian Wars. As well, most of those events and people are taken out of Herodotus and blown up into semi-fabricated, ridiculous, and even racist depictions. Artemisia was noteworthy enough for Herodotus to make mention of her and her actions at Salamis, Rise of an Empire has taken this, twisted it massively, and turned her into a lame SUPER EVIL villain. Spoilers ahead, but really, who was anticipating this movie?

The Origin Story

Rise of an Empire depicts Artemisia as a street girl whose family was raped and massacred by Greek soldiers (the reason she hates Greeks), saved by a Persian ambassador and trained to serve Darius as a super assassin.

Now, forget ALL of that. Its nonsense.

Herodotus first makes mention of Artemisia in Book 7 of his Histories:

I see no need to mention any of the other captains except Artemisia. I find it a great marvel that a woman went on the expedition against Hellas: after her husband died, she took over his tyranny, though she had a young son, and followed the army from youthful spirits and manliness, under no compulsion. [2] Artemisia was her name, and she was the daughter of Lygdamis; on her fathers' side she was of Halicarnassian lineage, and on her mothers' Cretan. She was the leader of the men of Halicarnassus and Cos and Nisyrus and Calydnos, and provided five ships. [3] Her ships were reputed to be the best in the whole fleet after the ships of Sidon, and she gave the king the best advice of all his allies

As you can see, its way different. Artemisia was royalty, she provided five quality ships to the Persian fleet, and gave Xerxes good counsel. There is no evidence of her knowing Darius, interacting with Xerxes before his assumption of the throne, or being "behind the scenes" manipulating Xerxes into invading Greece.

Herodotus is quite fond of Artemisia, really. In the movie she is depicted as cold, ruthless, bloodthirsty, etc. But this doesn't have any historical weight beyond lazy writers wanting us to really make sure we knew she was the villain.

The Sex

This is actually pretty brief. There is no record of Artemisia and Themistocles ever meeting, let alone participating in some, well, "aggressive negotiations". On a greater note, Artemisia was not the overall admiral of the Persian fleet anyway.

The Battle

Rise of an Empire gradually shows the strategically impeccable Artemisia continuing to be outfought by Themistocles unconventional naval tactics. By the climactically ridiculous depiction of the Battle of Salamis, Artemisia is shown to be losing her cool and rushing headstrong to join battle with the Greek fleet. This is also incorrect. Herodotus writes:

Tell the king, Mardonius, that I (Artemisia), who neither was most cowardly in the sea battles off Euboea nor performed the least feats of arms, say this: ‘Master, it is just for me to declare my real opinion, what I consider to be best for your cause. And I say to you this: spare your ships, and do not fight at sea. Their men are as much stronger than your men by sea as men are stronger than women.

In her wisdom, Artemisia was against Xerxes seeking battle against the Greeks at Salamis. While Xerxes appreciated this, he went with the majority of his other advisors and captains to fight.

Her actual participation at Salamis was a huge miss for the movie, mainly because the truth is much more interesting. The film depicts her and her Immortal bodyguard absolutely destroying the Greek marines until she engages in single, final showdown, combat with Themistocles, where she eventually falls to the great blade of democracy and freedom yeah go West!!. Yawn.

In actuality, in the confusion of the seaborne melee, Artemisia was pursued by an Attican ship. Wanting to escape capture or sinking, she chose to ram a friendly Persian vessel, specifically the one manned by the Kalyndians and their King. Even Herodotus admits that he is not sure if it was intentional or truly accidental, but it happened regardless. Three things happened from this:

1. She escaped

2. The Attican ship pursuing her figured she was an ally, after all she did just ram and sink a Persian vessel. The Attican captain did not pursue her further

3. Xerxes mistook her action as her ramming a Greek ship. Her ensign was noticeable to Xerxes, and no Kalyndian would survive her blue-on-blue incident to accuse her. Her "success" causes Xerxes to utter a now famous line: 'My men have become my women, and my women men."

Having survived Salamis and remained in Xerxes good opinion, she is last mentioned by Herodotus as advising the Persian King to return home, leave an army in Greece to wage the remainder of his campaign:

Sire, it is difficult for me to give the best advice to you, as you are seeking the best possible course of action, but in view of th epresent situation, it seems to me that you should go back home, an dif Mardonios wants and promises to do what he has suggested, leave him behind here with the men of his choice. For if he does subjugate this land as he claims he would like to do and thus succeeds in this plan, the success will be yours, by lord, since the conquest will be performed by your slaves. On the other hand, if the outcome is the opposite of what Mardonios thinks will happen, it will be no great misfortune, since you will survive and so will your power in Asia as far as your own house is concerned. And if you and your house survive, the Hellenes will have to run many races for their lives. Besides, if something happens to Mardonios, it is of no great consequence. And even if the Hllenes win, they will not win anything substantial by destroying your slave, while you will march home after you have burned Athens, and thus will have achieved the goal of your expedition.”

Hope this helps!