Theodor Fliedner was a 19th-century German Lutheran minister and missionary who revolutionized social work and nursing. Born in Eppstein, he served as a pastor in Kaiserswerth, where he addressed the needs of the impoverished and incarcerated. Alongside his wife Friederike and later Caroline Bertheau, he established the Kaiserswerther Diakonie, an institution that combined hospital care with training for deaconesses. His pioneering work in professionalizing nursing influenced many, including Florence Nightingale, and his deaconess movement eventually expanded into a global network of service.