BARBARI, Jacopo de'
(b. ca. 1445, Venezia, d. 1516, Bruxelles)

Portrait of Fra Luca Pacioli and an Unknown Young Man

c. 1495
Museo Nazionale di Capodimonte, Naples

Fra Luca Bartolomeo de Pacioli (sometimes Paciolo) (1446/7-1517) was an Italian mathematician and Franciscan friar, collaborator with Leonardo da Vinci, and seminal contributor to the field now known as accounting. He was also called Luca di Borgo after his birthplace, Borgo Santo Sepolcro, Tuscany.

The table is filled with geometrical tools: slate, chalk, compass, a dodecahedron model and a rhombicuboctahedron half-filed with water is hanging in the air. Pacioli is demonstrating a theorem by Euclid.