Carola, wife of Obelerio degli Antenori

Carola (fl. 811) was the Dogaressa of Venice by marriage to the Doge Obelerio degli Antenori (r. 804-811). She was politically active and exerted influence over the affairs of state. She was the first consort of a Venetian doge with the title and position of dogaressa of Venice. 
Life.
Carola was originally a Frankish countess and a lady-in-waiting to the empress of Charles the Great. She met Obelerio when he and his brother Beato visited the court of Charles in Aix-La-Chapelle. Charles gave his blessing to the union and declared it to be a political alliance and gave his protection to Venice. Carola was described as strong-willed, energetic and with an ability to create respect and obedience. She was somewhat disliked for the perceived Frankish influence she represented.
Carola participated in an legendary intrigue constructed by her brother-in-law Beato. According to legend, Beato married the Byzantine Princess Cassandra in order to replace Doge Obelerio and Dogaressa Carola with himself and Cassandra by support of the Byzantines. Upon the arrival of Cassandra to Venice, however, Carola destroyed the alliance between Beato and Cassandra by convincing Cassandra to engage in adultery with her youngest brother-in-law, Valentino. She did succeed, but reportedly fell in love with Valentino herself in the process. When a Byzantine fleet was sighted in the Adriatic Sea, the Doge felt threatened enough to send for Frankish assistance. His appeal to the Franks, however, insulted the Byzantines, which lead to the capture of Obelario and Carola as well as Beato and Cassandra, which were all imprisoned in Constantinople.