His mother was Tetrata of Lombardy , a daughter of the eldest son of Charlemagne , Pepin of Italy .
After his father 's death , Lambert III became a pretender to the County of Nantes seat .
Lambert III 's mother was Tetrata of Lombardy , a daughter of the eldest son of Charlemagne , Pepin of Italy .
After his father 's death , Lambert III became a pretender to the County of Nantes seat .