Contemporary documents prove that the interior was begun in 1508 by Cola Matteuccio da Caprarola, and the exterior completed in1516-1524by Ambrogio da Milano and Francesco di Vito Lombardo; the slender dome was not added till .1606; its plan is a Greek cross.
Strong claims have also been made on behalf of a fine profile portrait resembling Beatrice d'Este in the Ambrosiana; but this the best judges are agreed in regarding as a work, done in a lucky hour, of Ambrogio de Predis.
The painters especially recorded as Leonardo's immediate pupils during this part of his life at Milan are the two before mentioned, Giovanni Antonio Boltraffio and Ambrogio Preda or de Predis, with Marco d'Oggionno and Andrea Salai, the last apparently less a fully-trained painter than a studio assistant and personal attendant, devotedly attached and faithful in both capacities.
Documents show him, among other things, planning during an absence of several months from the city vast new engineering works for improving the irrigation and water-ways of the Lomellina and adjacent regions of the Lombard plain; ardently studying phenomena of storm and lightning, of river action and of mountain structure; co-operating with his friend, Donato Bramante, the great architect, in fresh designs for the improvement and embellishment of the Castello at Milan; and petitioning the duke to secure him proper payment for a Madonna lately executed with the help of his pupil, Ambrogio de Predis, for the brotherhood of the Conception of St Francis at Milan.
In the Sala dei Nove or della Pace above are the noble allegorical frescoes of Ambrogio Lorenzetti representing the effects of just and unjust government; the Sala delle Balestre or del Mappamondo is painted by Simone di Martino (Memmi) and others, the Cappella della Signoria by Taddeo di Bartolo, and the Sala del Consistorio by Beccafumi.
AMBROSE THE CAMALDULIAN, the common name of AMBROGIO TRAVERSARI (1386-1439), French ecclesiastic, born near Florence at the village of Portico.
The 14th century gives us Ugolino, Duccio di Buoninsegna, Simone di Martino (or Memmi), Lippo Memmi, Pietro and Ambrogio Lorenzetti, Andrea di Vanni (painter and statesman), Bartolo di Fredi and Taddeo di Bartolo.