Princess is a regal rank and the feminine equivalent of prince (from Latin princeps, meaning principal citizen). Most often, the term has been used for the consort of a prince, or for the daughter of a king or prince.
Louis IX, Landgrave of Hesse-Darmstadt: 11. Princess Amalie of Hesse-Darmstadt: 23. Countess Palatine Caroline of Zweibrücken: 1. Carola of Vasa: 24. Charles Frederick, Grand Duke of Baden (= 20) 12. Charles Louis, Hereditary Prince of Baden (= 10) 25. Landgravine Caroline Louise of Hesse-Darmstadt (= 21) 6. Charles, Grand Duke of Baden: 26.