FIRST WOMAN ADMIRAL IN THE MODERN WORLD
In the 1500s, Aceh (Acheh) was a sultanate at the northernmost tip of the island of Sumatra (now part of western Indonesia), as shown in green on this map:
Its position as a regional superpower controlling maritime travel through the Straits of Malacca put Aceh in direct conflict with Portugal, which captured the Malaysian Sultanate of Malacca in 1511. Aceh's goal was to ensure that the straits remained open only to Asian, not European, merchants; needless to say, the Portuguese saw things differently. Keumalahayati (whose dates of birth and death are not known) was the great-granddaughter of the first Sultan of Aceh, and the daughter of Admiral Muhammad Said Syah, and she no doubt learned from her father's example, if not also from his direct instruction, about how to run a naval fleet. She also attended the Aceh Royal Military Academy.
After her husband was killed in battle with the Portuguese, Keumalahayati formed and commanded a women's naval unit called Armada Inong Balee (The Widows' Fleet), staffed by war widows like herself and based in forts near a harbor that now bears her name.
In 1599, Keumalahayati led her all-woman force in response to an attack from a Dutch fleet, and after violent battles, succeeded in killing the Dutch commander and routing the attack. Eventually, the reigning Sultan appointed Keumalahayati as the First Admiral of his entire naval force.
At one point, Keumalahayati's forces sank a Portuguese flotilla consisting of six galleys. She also made strong inroads against the Dutch by sinking or capturing their ships. In 1600, a Dutch naval captain robbed an Aceh merchant ship off the coast of Aceh, and in June of 1601, Keumalahayati retaliated by ordering the capture and arrest of a Dutch admiral. After other Dutch naval maneuvers were thwarted by Aceh, the Dutch gave up the fight and, in August 1601, sent diplomatic letters of apology to Aceh, seeking a truce. Keumalahayati herself negotiated the peace treaty whereby she released Dutch prisoners and Aceh received 50,000 gulden in compensation for the initial robbery.
By 1602, Keumalahayati's reputation was such that England's Queen Elizabeth decided not to mess with her, but instead to go the diplomatic route in her attempt to open the Malacca Strait to the British Navy so that they could initiate trade with Java. The negotiations on the Aceh side were led by Keumalahayati, and the result was satisfactory to both parties.
In the end, Keumalahayati was killed in battle with the Portuguese, and I would guess that's exactly the way she would have wanted to go. She is considered an Indonesian national hero.
p.s. The format of this post is a little different than the others because it was the first one I wrote, even before I did my Theme Reveal. Don't let it throw you!