Bertha (born between 863 and 868 – March 925 in Lucca) was countess of Arles by marriage to Theobald of Arles, and margravine of Tuscany by marriage to Adalbert II of Tuscany. She served as regent of Lucca and Tuscany from 915 until 916 during the minority of her son Guy of Tuscany. She was described as beautiful, spirited and courageous, while her influence over her spouse was, coupled with ambition, attributed to have involved her husbands in many wars.
She was the second daughter of Lothair II, King of Lotharingia, by his concubine, Waldrada.[1]