László Batthyány-Strattmann, born on October 28, 1870, in Dunakiliti, Hungary, hailed from a distinguished Hungarian noble family. His early life was marked by personal hardships; his father left the family and converted to Protestantism, and his mother passed away when László was just twelve years old . Despite these challenges, he pursued a broad education, studying subjects such as agriculture, chemistry, philosophy, and music, before ultimately deciding to study medicine. He earned his medical degree from the University of Vienna in 1900 .​‍

In 1898, László married Countess Maria Theresia von Coreth zu Coredo und Starkenberg, a devout Catholic. Together, they had thirteen children. His wife played a significant role in managing the family's daily life and assisting in his medical endeavors . In 1902, László established a private hospital in Kittsee, Austria, adjacent to his family's castle. The hospital, equipped with modern facilities, provided free medical care to the poor, earning him the title "doctor of the poor." During World War I, he expanded the hospital to accommodate wounded soldiers .​‍

After inheriting the title of Prince and the family estate in Körmend, Hungary, in 1915, László converted a wing of the castle into a hospital specializing in ophthalmology. He continued to offer free medical services, financing the hospital and staff salaries from his own resources . A devout Catholic, he and his wife joined the Franciscan Third Order in 1916. László passed away from bladder cancer on January 22, 1931, in Vienna. Recognized for his unwavering dedication to the poor and sick, he was beatified by Pope John Paul II on March 23, 2003.