Theo Hios was born in the village of Trypi, Laconia, in 1908. During his school years, he lived in Sparta and later began his law studies in Athens. Disappointed by the prospects of the profession, he emigrated to the United States in 1929. During the years of the Great Recession, he worked in a restaurant and in his spare time, was trying to improve his English by reading philosophy books. In 1934, he began attending painting courses in departments supported by the Works Progress Administration (WPA) program and continued attending lithography, engraving and fresco painting courses until the end of the decade. Influences from expressionism, social realism and Mexican frescoes intersected in his works from that period. His themes included landscapes, portraits and urban landscapes, where the issue of labor is often evident through the depiction of workers or of their tools. As the United States entered World War II, Hios enlisted in the US Army and attended martial arts courses. He participated in battles in the Marshall Islands, Iwo Jima and Saipan and he was awarded a war medal for his contribution. During this period, he continued painting, depicting in symbolic and expressionist paintings the horror of war, a theme that also arose in some of his post-war works and upon his return to New York. He continued attending painting courses but soon decided to start his own drawing class attended by artists such as Theodoros Stamos, Aristodimos Kaldis, Nassos Daphnis, Michael Lekakis, as well as his sister, Katerina Lekaki, a dancer, painter and ceramist, who married Hios in 1947. In 1953, he made a six-month trip across Greece that had a major impact on his work, as aspects of the Greek landscape would dominate his drawings and paintings in the following years. In 1963, he began teaching at the New School for Social Research in New York, a position he held until 1994. His painting gradually shifted towards abstraction in a more intense manner since the early 1960s, and was fully manifested through the circular formations he drew up until the end of the 1970s. In these new images of concentric or divergent circles on square or circular canvases, Hios combined spiritual and cosmic elements such as the movement of the planets and stellar bodies with Byzantine painting tradition and rendered them with the painting language of his era. His works often have titles derived from ancient Greek mythology (e.g. Labyrinth, Mars, Apollo). Since 1979, after a trip to Yellowstone Park and, in 1981, following another trip to Greece, he turned again to representational painting. In 1998, he held his last retrospective exhibition at the Susan Teller Gallery in New York. He died in New York in 1999.