The historian Hiroshi Takayama concludes that Charles' dominion "was too large to control". Nevertheless, economic links among his realms strengthened during his reign. Provençal salt was transported to his other lands, grain from the Regno was sold in Achaea, Albania, Acre and Tuscany, and Tuscan merchants settled in Anjou, Maine, Sicily and Naples. His highest-ranking officials were transferred from their homelands to represent him in other territories: his senechals in Provence were from Anjou; French and Provençal noblemen held the highest offices in the Regno; and he chose his vicars in Rome from among southern Italian and Provençal nobles. Although his empire collapsed before his death, his son retained southern Italy and Provence.