Catherine Michaela was the daughter of Philip II, ruler of the vast Spanish Empire, and his third wife, the French princess Elisabeth of Valois.

Though her father did not attend her christening and was not as rejoiced at the birth of a daughter as he had been with her elder sister, Isabella Clara Eugenia, she had a good relationship with him.

On 1 August 1591, Charles Emmanuel and Catalina Micaela appointed Tomás Fernández de Medrano as their Secretary of State and War, a move that proved pivotal for relations between the Duchy of Savoy and the Spanish Monarchs.

Catherine Michaela was initially unpopular because of her arrogance and attempts to introduce Spanish pomp, ceremony and way of dress to the court in Turin.

Catherine Michaela also benefited cultural life in Savoy, founded many new buildings including an art gallery.