Prince

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"She's rich..."

―Luke Skywalker, persuading Han Solo to rescue the imprisoned Leia Organa on the first Death Star^[src]

Prince was a noble title. The feminine equivalent title was Princess. It was used to indicate the heir of a Monarch, such as Prince Isolder, Princess Syayna or Princess Leia Organa; the heir of a Chieftain, such as Princess Kneesaa a Jari Kintaka; or a noble of great power and wealth, such as Prince Xizor. Additionally, a prince could also rule independently or mediatized to a greater lord.

There were also titles such as Princess of Theed, which was owned by numerous persons, including the future Queen of Naboo (the world of Theed), Padmé Amidala. However, this title did not mean that Padmé's parents were the King and Queen, it was a title which later gave her an advantage in the monarch elections of 32 BBY.

In the case of the Galactic Empire of 130 ABY, it was the heir of an emperor, rather than a monarch, with Princess Marasiah Fel.

It was the title of the nobility for members of the Hapan Consortium such as Prince Isolder. The Tof species seemed to possess the title of Princes who were also military leaders of their invasions.