Born in the castle of Grazzano Visconti of Vigolzone, Piacenza, Allegra Caracciolo di Castagneto is the daughter of Adolfo Caracciolo, a Neapolitan noble, and of Anna Visconti di Modrone, a family of nobility in Milan. And she is also the niece of the director Luchino Visconti.
In 1975 Allegra Caracciolo di Castagneto married Umberto Agnelli, brother of Gianni Agnelli, and thus became sister-in-law of her cousin Marella Agnelli, wife of Gianni Agnelli. She had two children from the marriage: Andrea (1975) and Anna (1977).
Being called 'Donna Allegra', Allegra Agnelli lived a very low profiled life in Turin with her husband and their children until 2004, when her husband Umberto Agnelli died and she became widow.
Like her sister-in-law Marella Agnelli, Allegra Agnelli is known for her beauty and timeless elegant style and lives a priviledged life of socialite, but she is also dedicated for public causes, like animal protection and cancer researches.
In 2004, Allegra Agnelli received an honorary degree in Veterinary Medicine University of Turin. This is due to her persistent commitment to animals. And in the same year, the then President of the Republic, Carlo Azeglio Ciampi, presented her with the Gold Medal of Merit of Public Health. - Always Ciampi, a year later, awarded her the 2005 Peace Prize.