The Italian Renaissance man Giulio Cesare Polerio was prominent in which of these fields?

Giulio Cesare Polerio (1550-1610) was an Italian chess player and expert in the theory of the game. He was sometimes also known as "Lancianese", which points to him being born in the town of Lanciano, in the southern Italian region of Abruzzo.

The first published mention of him occurs posthumously, in 1634, in an account by fellow chess player Alessandro Salvio (1575-1640). However, a thorough investigation into his codexes was not to appear until 1874, under the auspices of the Dutchman Antonius van der Linde.

Polerio was the instigator of several moves still used in the game today. These include the famous Sicilian Defence, which was, incidentally, conceived as a counter to the bizarrely named Fried Liver Attack (1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nxd5 6.Nxf7 Kxf7) which is first recorded in a game he played in 1610.