When Isabella arrived in Mantua in February 1490, the most powerful individual after her husband was Francesco Secco (or Sicco), a long-established and authoritative figure. Secco had been uomo di fiducia of the previous marchesi Lodovico II and Federico I, and in 1451 had married Caterina Gonzaga, Lodovico’s illegitimate daughter. After Francesco Gonzaga’s succession, Secco was named luogotenente generale dello stato with full powers in 1485.1 However, as the marchese gained confidence as a ruler and with Isabella by his side capable and available to support him in that role, Francesco Secco’s place at the pinnacle of power became precarious. Isabella ‘seems to have recognised the serious threat behind Secco’s domination’, and her determination to govern fully alongside her husband dictated that Secco’s power could not continue.2 The young ruling couple may have resented the influence of an elderly manipulator from past regimes. They may also have become alarmed about Secco’s might, as he was in possession of virtually a private army with which to exercise rough justice.3 Furthermore, Secco’s position had barred the access to influence of Francesco’s uncles Rodolfo, Lodovico, and Gianfrancesco. Indeed, along with his brother Stefano, castellan of Mantua, Secco may have been responsible for the fabrication of charges of treason brought against the marchese’s uncles in 1487, leading to their banishment from

1 See letters patent and letter of Francesco Gonzaga to Francesco Secco, Gonzaga, 27 May and 16 June 1485, Patenti, L. 3, ff. 146r-147r. Fermo Secco d’Aragona, ‘Francesco Secco, i Gonzaga e Paolo Erba. Un capitolo inedito di storia mantovana’, ASL, 6 (1956), 210-261, p. 257. For Francesco Secco’s life see Secco d’Aragona; Gianfranco Ferlisi, ‘Le vicende di un cortegiano del ‘400: Francesco Secco da “fedelismo” di Ludovico II a protagonista di un’oscura congiura di palazzo’, CM, 110 (2000), 33-37; and Marilena Dolci, ‘Congiure e misteri alla corte dei Gonzaga. Il processo a Francesco Sicco. Prima parte. La fuga di Francesco Sicco’, CM, 120 (2005), 23-47 and ‘Congiure e misteri alla corte dei Gonzaga. Il processo a Francesco Sicco. Seconda parte. Le congiure’, CM, 123 (2007), 17-50.