According to legend Saint Ursula was a British princess who made a pilgrimage to Rome with 11,000 virgin companions. She returned with them to Cologne, where they were all martyred. Saint Ursula is shown here, in yellow and holding a flag with her emblem, watching her companions embark on the return voyage. The girls carry bows and arrows, the instruments of their martyrdom. The building at the left is based on the Tempietto di San Pietro in Montorio, Rome. The canvas was painted in 1641 for Fausto Poli, who was made a cardinal by Pope Urban VIII in 1643.
A comparison of this picture with Claude's 'Seaport with the Embarkation of the Queen of Sheba', also in the National Gallery, illustrates Claude's evolution of the theme of the seaport. In the latter picture, there is a move towards greater simplicity and unity of design and the left/right symmetry becomes more pronounced.