The Holy Roman Emperor Ferdinand II invited him to Vienna to paint portraits of the Imperial family and granted Sustermans and his brothers patents of nobility.

[3] On 5 January 1622, he delivered his first surviving documented work for the Medici, a portrait of Maria Maddalena of Austria, the widow of Grand Duke Cosimo II (now in the Royal Museum of Fine Arts of Belgium Brussels).

[6] He wrote a letter to the Emperor pleading for him and his brothers Jan, Nicolaes, Frans, Vincent and Cornelis to be raised to the nobility.

[1] He traveled to Rome with his brother Frans, where in 1627 he painted portraits of Pope Urban VIII and most of the cardinals at the Vatican.

He traveled to Rome in 1645 in the following of Cardinal Giancarlo de' Medici, the second son of Grand Duke Cosimo II.

Some of the collaborators in his workshop established a name for themselves including the brothers Valore and Domenico Casini, Valerio Marucelli, Francesco Bianchi Buonavita and Giovanni Lionardo Henner.

In 1635 he married Maddalena di Cosimo Mazzocchi, from which union were born a son Francesco Maria and a daughter Vittoria.

[2][12] Sustermans did not share the Flemish preference for concentrating on the details of the sitters' clothes and rather favored a monumental simplicity in form.

In Italy his style started to reflect the contact with Florentine painters such as Cristofano Allori and Domenico Passignano.

His Maria Maddalena of Austria (Wife of Duke Cosimo II de' Medici) with her Son, the Future Ferdinand II (Flint Institute of Arts, 1623) shows his familiarity with the work of Scipione Pulzone, in particular his Portrait of Christine of Lorraine (Uffizi).

[3] During his years in Vienna in 1623 and 1624 he painted in a more painterly style which possibly was under the influence of the works of Hans von Aachen and Josef Heintz.

Later, his work became more Baroque, under the influence of Flemish painters such as Rubens, Anthony van Dyck and Cornelis de Vos.

His Portrait of Prince Waldemar Christian of Denmark (Galleria Palatina) shows the influence of Rubens.

Suttermans was for seven years in possession of Titian's Portrait of Pietro Aretino (Florence, Pitti), which was in the collection of the Medici.

[3] It was commissioned by Elia Diodati, a jurist who lived between Paris and Geneva and was a good friend of Galileo.

The portrait is a half bust showing Galileo's face on which the light source falls and looking upwards outside the frame.

An example is the full-length Portraits of Vittoria della Rovere with the young Cosimo III de Medici (Museo Nazionale di Palazzo Mansi, 1646).

The reason behind this may have been an increased dependence on his workshop, either because Sustermans was regularly travelling or because of the Grand Duke's imposition of standard prices for anything other than full-length portraits.