Princess is the feminine form of prince

Prince

Prince is a general term for a ruler, monarch or member of a monarch's or former monarch's family, and is a hereditary title in the nobility of some European states. The feminine equivalent is a princess...

 (from Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 princeps

Princeps

Princeps is a Latin word meaning "first in time or order; the first, chief, the most eminent, distinguished, or noble; the first man, first person."...

, meaning principal citizen). Most often, the term has been used for the consort of a prince, or his daughters.

For many centuries, the title "princess" was not regularly used for a monarch's daughter, who might simply be called "Lady" or a non-English equivalent; Old English

Old English language

Old English or Anglo-Saxon is an early form of the English language that was spoken and written by the Anglo-Saxons and their descendants in parts of what are now England and southeastern Scotland between at least the mid-5th century and the mid-12th century...

 had no female equivalent to "prince", "earl", or any royal or noble aside from the queen, and the women of nobility bore the title of "Lady".

As women have slowly gained more autonomy through European history

History of Europe

History of Europe describes the history of humans inhabiting the European continent since it was first populated in prehistoric times to present, with the first human settlement between 45,000 and 25,000 BC.-Overview:...

, the title of princess has become simply the female counterpart of prince and does not necessarily imply being controlled or owned by a prince.