The Principality of Mariana was one of the former States of Rodenia. It existed between 1607 and 1778.
The Principality of Mariana was founded in 1607 by Prince Massimo of Mariana, a son of Francesco I of Viola. The state was a regional power, and up to 1630 was even more powerful than Viola. The territory expanded through minor wars in the 1600s. During the War of the Great Coalition, Mariana remained neutral, although it did supply the Coalition with supplies and food during the war, which gained them friendly relationship with Viola, Ravenna, Santa Maria, and Assiria. In 1778, Princess Carlotta of Mariana married King Charles II of Viola and both their countries were united under the flag of Viola. In present times, Mariana is used to refer to the western part of Viola.