Dmitri Ilyich Ulyanov (Russian: Дми́трий Ильи́ч Улья́нов; 16 August [O.S. 4 August] 1874 – 16 July 1943) was a Russian and Soviet physician and revolutionary, the younger brother of Aleksandr Ulyanov and Vladimir Lenin. At the beginning of the First World War, Ulyanov was mobilized into the army. He served as a medical officer in Sevastopol, in Odessa, and on the Romanian front, continuing his revolutionary activities on the side. In 1916 he married Antonia Ivanovna Neshcheretova. He had a son, Viktor, and a daughter, Olga.