Barbarossa Hayreddin Pasha (Turkish: Barbaros Hayreddin Paşa or Hızır Hayreddin Paşa; also Hızır Reis before being promoted to the rank of Pasha and becoming the Kaptan-ı Derya (Fleet Admiral) of the Ottoman Navy) (c. 1478 – 4 July 1546) is a Turkish privateer and Ottoman admiral who dominates the Mediterranean for decades.

He is born on the Ottoman island of Midilli (Lesbos/ Mytilini in today's Greece) and dies in Istanbul, the Ottoman capital.

His original name was Yakupoğlu Hızır (Hızır son of Yakup).

Hayreddin, which literally means Goodness or best of the Religion [of Islam]) is an honorary name given to him by Sultan Suleiman the Magnificent.

He becomes known as Barbarossa (Redbeard in italian) in Europe, a name he inherits from his older brother Baba Oruç (Father Aruj) after Oruç is killed in a battle with the Spanish in Algeria.

This name sounds like "Barbarossa" (Redbeard) to the Europeans, and Oruç did have a red beard.

The nickname sticks then also to Hayreddin's Turkish name, in the form Barbaros.