Born in Amarante, he was on the Architecture Course of the Lisbon School of Fine Arts, not having completed it.
He left for Paris in 1906, a city where he stayed until 1914 at which time he returned to Portugal, partly due to the breaking out of the war. Taking
shelter in Amarante he lived with other artists who had set up in the meantime in Portugal: Sonia and Robert Delaunay. He died early in Espinho, the
victim of pneumonia.
Amadeo is the major artist of Portuguese modernism and probably of the 20th century, having carried out in a short space of time a vast work which
proved permeable to the main strains of painting of his time, thereby proving himself in relation to the colleagues of his generation, revealing himself as a
pioneer on the national stage and discovered only at a later date by Portuguese artists. The contemporary praise stemmed from Almada Negreiros.
His career began with his virtuous, stylised drawing of albums of illustrations and caricatures, whereafter he dedicated himself to painting.
Keen experimentation is a constant aspect of his whole pictorial journey, leading him to pointillist attempts at orphism which derived from the
relationship with the Delaunay, involving a form of expressionist connotation. Cubism progressively attracted him, bringing out forms and intertwining
planes, geometrising the natural elements, researching the space. In Amarante there were already cultural, traditional and popular aspects which
served as the theme for the compositions. These acquire an abstract guise, then in a final stage proposing collages, basic materials such as mirrors,
hairclips, sand etc. Totally reworking the pictorial procedures, in this way assimilated with the Dadaist stream. All the movements in the second decade of
the 20th century were to be found in the works of Amadeo, making them the maximum limit which Portuguese painting attained in terms of the
international references of that time.