Shirin was a wife of the Sassanid Persian Shahanshah, Khosrow Parviz. In the revolution after the death of Khosrow's father Hormizd IV, the General Bahram Chobin took power over the Persian empire. Shirin fled with Khosrow to Syria, where they lived under the protection of Byzantine emperor Maurice. In 591, Khosrow returned to Persia to take control of the empire and Shirin was made queen. She used her new influence to support the Christian minority in Iran, but the political situation demanded that she do so discreetly. Initially she belonged to the Church of the East, the so-called Nestorians, but later she joined the miaphysite church of Antioch, now known as the Syriac Orthodox Church. After conquering Jerusalem in 614, amidst the Byzantine–Sasanian War of 602–628, the Persians captured the True Cross of Jesus and brought it to their capital Ctesiphon, where Shirin took the cross in her palace.
Long after her death Shirin became an important heroine of Persian literature, as a model of a faithful lover and wife. She appears in the Shahnameh and the romance Khosrow and Shirin by Nizami Ganjavi, and is referred to in very many other works.