Tanzio da Varallo may have first trained in his father's sculpture workshop and with his brother, a fresco painter. His dramatic, tense manner combined the elegance of his native Lombard late Mannerism with Caravaggio's realism, a style he discovered while visiting Rome before 1615. Recent discoveries of Tanzio's paintings have lent credence to his early biographer L.A. Costa's reports that he studied in the academies of Rome and in 1627 "left works, both of figures and landscapes, in Naples, in several places in Puglia, in Venice and in Vienna."
From 1616 to 1620, Tanzio and his sculptor brother decorated two chapels in the Sacro Monte at Varallo with stage-like tableaux-vivants. Using freestanding terracotta sculptures combined with vivid frescoes, they illustrated scenes from Christ's passion.
In his drawings, Tanzio displayed the highly refined and meticulously finished technique associated with Renaissance draftsmanship. The plasticity of his drapery studies reflected his experience with sculpture. He displayed the height of his drama and emotion in paintings such as his vast Battle of Sennacherib of 1629, in which contorted figures lit by violent slashes of unnatural light crowd the foreground.