 After the death of his brother, John IV in 1008, his mother took over the regency for her grandson, Leo's nephew, John V. Leo challenged his mother for the regency, successfully displacing her by 1017.As regent, Leo gave away public land to Kampulus, son of Docibilis, of the prominent Kampuli family, probably in an effort to gain the family's support.The fisheries owned by the duke on the island of Ventotene and Santo Stefano in the Pontines were granted to Kampulus.