LONDON — Many young people leading safe, comfortable lives in the West take up causes like the environment or gender equality. Fewer devote themselves to the plight of Kurds in Syria’s brutal civil war. Fewer still travel there to join the fighting, and those who do are usually men.

But Anna Campbell, a young woman from southern England, did all of that. Last week, as the Turkish military and its Syrian rebel allies hammered their way into Afrin, in northwestern Syria, Ms. Campbell died for her commitment — the eighth Briton and the first British woman to be killed fighting alongside Kurdish forces.

In Britain, Ms. Campbell, 26, was active in causes like animal rights and environmental protection, but until recently, she had no personal connection to the Kurds. Yet she was deeply moved, family and friends said, by the fight to defend an autonomous, mostly Kurdish region in northern Syria, known as Rojava, whose leaders advocate a secular, democratic and egalitarian politics, with equal rights for women.

“She was somebody who saw the injustices of the world and the plight of the weak and vulnerable and disempowered, and she also saw the idealism, the amazing utopian vision of Rojava, and she found those two elements irresistible,” her father, Dirk Campbell, said in an interview. “She wanted to prevent that from being stamped out, which Turkey and Syria are trying to do.”