A Flemish background also offers an explanation for the stylistic characteristics of de Roelas' work which had been explained traditionally by a presumed trip to Venice and an apprenticeship with a follower of Titian.
It is known that in 1598 he worked in Valladolid in the commemorative ceremonies for the death of king Philip II of Spain, contributing to the design of his funerary monument.
De Roelas contributed to Sevilian painting of the early 17th century what was formerly interpreted as the expressive and technical aspects of the Venetian art of Titian and Veronese, causing his paintings to be considered Italianate in their variegated and theatrical compositions, their richness and warmth of colour ranges, the use of broad and bold brushstrokes and their unusual size.
[8] In light of recent scholarship, however, scholarly consensus is that Roelas' oeuvre is better understood in the context of Flemish painting than in the supposed influence of the Venetian school.
[10] Through its interest in the study of nature, de Roelas's work forms a transition from the artificiality of Mannerism to the naturalistic realism of Spanish Baroque.
[11] His masterpieces include Martyrdom of St. Andrew[12] and El Transito de San Isidoro (Death of St. Isidore),[13] an altarpiece residing in the Church of San Isidore;[14][15] another of his finest works is the painting Santiago at the Battle of Clavijo, hung in the Chapel of Santiago in Seville Cathedral, which represents the saint riding victoriously over the Moors.
[17] The writer Richard Ford, well-versed in Spanish art, was especially impressed by the picture of the Conception (Concepción), in the Academy, and by three in the chapel of the University at Seville.