The present essay shows the results of a research carried out mainly on the Fund Tribunal of the Consistory, of the State Archives of Palermo, inherent to the inheritance of the post of notary master of the Royal Chancellery held from 1491 to 1523 by the royal knight Giovan Luca Barberi, author of Capibrevi, a work strongly desired by the central power to investigate the abuse of Sicilian feudalism, with regard to the legitimate possession of the feuds. By investigating the family relationships of the royal army, the mechanism that allowed the Lanza family, barons of the Mojo, in the person of Petruccio, husband of the illegitimate daughter of Barberi, to succeed and gain access to the prestigious post of notary of the Royal Chancellery, has been identified. so in the coveted domain of the royal administration at the expense of Giovan Battista Riga, also heir of Barberi as a spouse of the legitimate and natural daughter, despite a pronouncement of Emperor Charles V in his favor. What emerges is the age-old quarrel which saw for centuries the royal power, far from the island, and the Sicilian feudal lords defending their privileges through a cross-section of private life that allows us to shed light on economic interests and the representation of power of two families, the Barberi and the Lanza del Mojo.
Keywords: Giovan Luca Barberi, Lanza del Mojo, Master notary, Giovanni Battista Riga, Royal Chancellery.