Hormizd was a Sassanid Persian

Sassanid Empire

The Sassanid Empire , known to its inhabitants as Ērānshahr and Ērān in Middle Persian and resulting in the New Persian terms Iranshahr and Iran , was the last pre-Islamic Persian Empire, ruled by the Sasanian Dynasty from 224 to 651...

 prince, the third son of King Hormizd II

Hormizd II

Hormizd II, was the eighth Persian king of the Sassanid Empire, and reigned for seven years and five months, from 302 to 309. He was the son of Narseh .Almost nothing is known of his reign...

 and brother-in-law of King Shapur II

Shapur II

Shapur II the Great was the ninth King of the Persian Sassanid Empire from 309 to 379 and son of Hormizd II. During his long reign, the Sassanid Empire saw its first golden era since the reign of Shapur I...

. Imprisoned by him, he was freed by his wife in 323 and escaped to Constantinople

Constantinople

Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

, where Emperor

Roman Emperor

The Roman emperor was the ruler of the Roman State during the imperial period . The Romans had no single term for the office although at any given time, a given title was associated with the emperor...

 Constantine I

Constantine I

Constantine the Great , also known as Constantine I or Saint Constantine, was Roman Emperor from 306 to 337. Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issued the Edict of Milan in 313, which proclaimed religious tolerance of all...

 helped him and gave him a palace near the shore of the Marmara Sea  This palace became an important toponym of the city: its neighborhood (where the mosque

Mosque

A mosque is a place of worship for followers of Islam. The word is likely to have entered the English language through French , from Portuguese , from Spanish , and from Berber , ultimately originating in — . The Arabic word masjid literally means a place of prostration...

 of Little Hagia Sophia

Little Hagia Sophia

Little Hagia Sophia , formerly the Church of the Saints Sergius and Bacchus , is a former Eastern Orthodox church dedicated to Saints Sergius and Bacchus in Constantinople, later converted into a mosque during the Ottoman Empire....

 still stands) was known in Byzantine

Byzantine

Byzantine usually refers to the Roman Empire during the Middle Ages.Byzantine may also refer to:* A citizen of the Byzantine Empire, or native Greek during the Middle Ages...

 times as en tois Hormisdou , meaning "near the houses of Hormisdas". The Palace became later the private residence of Byzantine Emperor Justinian I

Justinian I

Justinian I ; , ; 483– 13 or 14 November 565), commonly known as Justinian the Great, was Byzantine Emperor from 527 to 565. During his reign, Justinian sought to revive the Empire's greatness and reconquer the lost western half of the classical Roman Empire.One of the most important figures of...

, before his accession to the throne.

In 363, Hormizd served against Persia in the army of the Emperor Julian

Julian the Apostate

Julian "the Apostate" , commonly known as Julian, or also Julian the Philosopher, was Roman Emperor from 361 to 363 and a noted philosopher and Greek writer....

 (361–363); in turn his son, of the same name, later served as proconsul (Ammianus Marcellinus

Ammianus Marcellinus

Ammianus Marcellinus was a fourth-century Roman historian. He wrote the penultimate major historical account surviving from Antiquity...

26. 8. 12).