In the 1870s, on Björkö, a Swedish island, archeologists discovered a Viking settlement at the excavation site Birka. Grave Bj.581 included the remains of two horses, “a sword, an axe, a spear, a battle knife, two shields and 25 arrows strong enough to pierce armour.” It was clearly the grave of a warrior.

The assumption, of course, was that the warrior was a man. However, in 2013, bone analysis concluded the skeleton was female. The unnamed woman warrior of Birka is only one of many cases of mistaken identity hiding women’s military contributions throughout the long history of warfare detailed by Sarah Percy in “Forgotten Warriors.”

Raised in Edmonton and now a University of Queensland professor of international relations in Australia, Percy expertly addresses the erasure of women’s involvement in war from a global perspective, writing that the history of women warriors was “often dismissed, denied and even actively suppressed.”

In fact, from the 16th century through to the end of the 19th century, European battlefields were full of women motivated to fight. Some were leaders, like Queen Isabella of Spain (1451-1504), who managed logistics and military equipment, and was known to ride in armour. And Queen Njinga of Ndongo, modern-day Angola (1582-1663), was skilled with a battle-axe and commanded troops for 40 years, using guerrilla tactics to disrupt the slave trade. Even Empress Maria Theresa of Austria (1717-1780) took an interest in all aspects of the military “from dress to discipline and tactics to weapons,” and complained that her 16 pregnancies “held her back from going to war herself.”

Between 1650 and 1850, women soldiers dressed as men fought in armies all over the world: Britain, France, Russia, and on both sides of the American Civil War. As Percy explains, “they were not just convincing in their guises as men, they were convincing as soldiers.”

By the mid-19th century in West Africa, an all-female force known as the Amazons of Dahomey trained in a variety of fighting techniques that included hand-to-hand combat with machetes, muskets and spears, their fingernails sharpened into points.

Throughout the early 20th century, the division between “out there” and “at home” had been drawn, with only women nurses permitted near battle. And, in America, the struggle for suffrage was tied to military service: a ploy of “bullets for ballots” ensured that by excluding women from the military they would also be denied the right to vote.

Yet, by the First World War, British women were mobilizing along military lines, enrolling in auxiliaries such as the Women’s Army Auxiliary Corps with more than 80,000 volunteers, upsetting retrenched expectations about gender. Around the same time in Russia, women dressed as men went to the front where they fought in the infantry and cavalry, and served as medics. In fact, by 1915, the Russian press reported that women were a common sight in battle.

In 1943, there were 56,000 British women working with anti-aircraft batteries, a male commander noting that “They are tough and can stick hardships every bit as well as the men.” Women spies who belonged to Britain’s Special Operations Executive were permitted to engage in combat because they worked outside of regular military and intelligence channels.

By the end of the Second World War, about a million women had served in the Soviet Union’s Red Army as gunners, fighter pilots — including the storied air regiment nicknamed “Night Witches” — and snipers. One of the war’s most decorated snipers, Lyudmila Pavlichenko, was “credited with 309 enemy kills.”

Rebel movements have often welcomed women combatants and have used them for subterfuge. Like the Sandinistas in Nicaragua, who sent “messages in the form of a tampon” to evade the National Guard. Soldierly bravado about danger is also demonstrated. As one female Tamil Tiger said, “One day we will all die so why be scared?”

More recently, countries have opened combat roles to women: the Netherlands in 1982, Denmark in 1988 and Canada in 1989. Canada, in fact, examined the historical record and determined that women combatants during the Second World War were “armed, suffered loss of life and injury, inflicted death and injury on others. In short, women were indistinguishable from men in terms of performance.”

Percy’s great strength is the impressive scope and detail of her research. She deftly demonstrates “that women were part of the warp and weft of war … and that they survived and even thrived” in its theatre.

Janet Somerville is the author of “Yours, for Probably Always: Martha Gellhorn’s Letters of Love & War 1930-1949,” also available in audio, read by Tony Award-winning Ellen Barkin.