Active warfare throughout history has mainly been a matter for men, but women have also played a role, often a leading one. While women rulers conducting warfare was common, women who participated in active warfare was rare. The following list of women in war and their exploits from about 1800 up to about 1899 can only indicate the involvement of women, some of them due to the circumstances of their birth or family connection, others by force of circumstance from humble origins.
Only women active in direct warfare, such as warriors, spies, and women who actively led armies are included in this list.
1808: Agustina de Aragón defends Spain during the Spanish War of Independence. During the bloody sieges of Saragossa, French General Jean-Antonie Verdier started the attack with a twenty-seven-hour bombardment of Zaragoza. At the Portillo Gate, most of the Spanish defenders had been killed or wounded, and on 2 July 1808 a French column launched an assault on the unmanned Portillo Gate battery. Observing the danger, twenty-two-year-old Agustina rushed forward to a twenty-four-pound cannon, retrieved the still-burning wick from the hands of a fallen gunner, and fired the cannon loaded with grapeshot at the advancing French column that decimated it and gave time to arrive Spanish reinforcements from a near battery to reject the attack. Agustina herself explained the facts in a memorial signed in Sevilla city in date 12 August 1810.
1808-1809: Elisa Bernerström enlists in the Swedish army dressed as a man because "She had decided to live and to die with her husband", the soldier Bernhard Servenus; she participates in the war between Sweden and Russia about Finland, and during one battle, she collected the ammunition of the Russians and gave them to her comrades. She is later discovered, fired but decorated with a medal for bravery in battle.
1815: William Brown (birth name unknown), a Royal Navy sailor, is discovered to be a woman. She is the first black woman to serve in the Royal Navy.
1815: Several women are found dead in British uniforms after the Battle of Waterloo, among them Mary Dixon, who dies in service after having served sixteen years in the British army dressed as a man 
1817: La Pola is executed by the Spanish after having served as a spy during the Colombian war of Independence
1822: Angelique Brulon, a female soldier who had in defence of Corsica from 1792–1799, is promoted to lieutenant. She had originally fought while disguised as a man, but eventually fought openly as a woman. She retires the same year.
1831: Countess Emilia Plater creates her own group to fight in the Polish November Uprising. She becomes commanding officer of a company of infantry in the rank of captain. She dies from illness contracted during a forced march in December 1832. Several other women served openly as soldiers during this Polish rebellion against Russia, although not many are named; Soltyk reported that a beautiful girl of eighteen fought at the Russian crossfier at the Vola trenches in Warsaw the 4th September 1831, and he added that "there where not one troop of our army, where not one or more of these heroines fought."
1838-1839: Johanna Martens serve in the Dutch army dressed as a man to be near to her lover, a soldier.