Agunot (Agunah, sing., meaning anchored in Hebrew) is a Jewish term describing women who cannot remarry because their husband has disappeared. According to Jewish law (Halacha) a woman can get out of the marriage only if the husband releases her by granting a divorce writ (Get), if he dies, or if his whereabouts is not known. Women whose husbands cannot be located, and who have not been granted a Get, are considered Agunot. The Agunah phenomenon was of major concern in East European Jewry and much referred to in Hebrew and Yiddish media and fiction. Most nineteenth-century Agunot cases came from Eastern Europe, where most Jews resided (twentieth-century Agunot were primarily in North America, and will be the subject of a forthcoming book). Seven variations of Agunot have been identified: Deserted wives; women who refused to receive, or were not granted, a Get; widowed women whose brothers-in-law refused to grant them permission to marry someone else (Halitza); women whose husbands remains were not found; improperly or incorrectly written Gets; women whose husbands became mentally ill and were not competent to grant a Get; women refused a Get by husbands who had converted to Christianity or Islam. The book explores the reasons for desertion and the plight of the left-alone wife. Key is the change from a legal issue to a social one, with changing attitudes to philanthropy and public opinion at the fore of explanation. A statistical database of circa 5000 identified Agunot is to be published simultaneously in a separate companion volume (978-1-78976-167-2).