That regency he had usurped from Gian Galeazzo's mother, and he was now in a fair way to usurp the throne itself.

He kept his nephew virtually a prisoner in the Castle of Pavia, together with his young bride, Isabella of Aragon, who had been sent thither by her father, the Duke of Calabria, heir to the crown of Naples.
1 Touching Lodovico Maria's by-name of "Il Moro"-- which is generally translated as "The Moor," whilst in one writer we have found him mentioned as "Black Lodovico," Benedetto Varchi's explanation (in his Storia Fiorentina) may be of interest.

He tells us that Lodovico was not so called on account of any swarthiness of complexion, as is supposed by Guicciardini, because, on the contrary, he was fair; nor yet on account of his device, showing a Moorish squire, who, brush in hand, dusts the gown of a young woman in regal apparel, with the motto, "Per Italia nettar d'ogni bruttura"; this device of the Moor, he tells us, was a rebus or pun upon the word "moro," which also means the mulberry, and was so meant by Lodovico.

The mulberry burgeons at the end of winter and blossoms very early.

Thus Lodovico symbolized his own prudence and readiness to seize opportunity betimes.
Gian Galeazzo thus bestowed, Lodovico Maria went calmly about the business of governing, like one who did not mean to relinquish the regency save to become duke.