The early 20th century was marked by the reign of Emperor Haile Selassie "(Ras Tafari)". Haile Selassie I was born to parents with ethnic links to three of Ethiopia's Afroasiatic-speaking populations: the "Oromo" and "Amhara", the country's two largest ethnic groups, as well as the Gurage. He came to power after Iyasu V was deposed, and undertook a nationwide modernization campaign from 1916, when he was made a "Ras" and Regent ("Inderase") for the Empress Regnant, Zewditu, and became the "de facto" ruler of the Ethiopian Empire. Following Zewditu's death, on 2November 1930, he succeeded her as emperor. In 1931, Haile Selassie endowed Ethiopia with its first-ever Constitution in emulation of Imperial Japan's 1890 Constitution, through which the Central European model of unitary and homogenous ethnolinguistic nation-state was adopted for the Ethiopian Empire.