I’d like to second Wu Zetian and Queen Victoria.
Addition remarkabe women include:
Empress Cathrine the Great of Russia. A Protestant German Princess, she managed to overthrow her husband to become Empress of the Orthodox Russian Empire. During her rein she passed many reforms that lead Russia into a golden age of culture.
Empress Theodora of the (Eastern) Roman Empire. From commoner to co-ruler of the Roman Empire she was perhaps the most important woman in the history of the Roman Empire. She stood in on many of her husbands councils, when she spoke all listened. Theodora also singlehandedly saved her husbands rein during the Nika Riots, when she stood on the docks and refused to flee with the rest of the court. “Purple is the noblest shroud” indeed.
Eleanor Roosevelt First Lady of the United States of America. Perhaps no woman had done more to shape the role of the modern First Lady. After her husband contracted polio she became very active in her husband’s political career, making appearances and speechs on Franklin’s behalf. She also was an ardent defender of the poor and minorities often advocating on their behalf to the President. After her husband’s death she went on to become one of the US’s delegates to the United Nations.
Edith Wilson, First Lady of the United States of America and arguably the country’s first female President. In 1919 sitting President, Woodrow Wilson, suffered a stroke leaving him completely bedridden. From that point on Edith Wilson screened all matters of state, deciding what was important enough to bring to the President, becoming de facto President herself.
This only a small sampling of some of the truly fascinating leading of women of history.