Pesto is a sauce that originates in the city of Genoa northern Italy. The name is the contracted past participle of pestâ ("to pound, to crush", from the Latin root pestle), in reference to the crushed herbs and garlic in the sauce.
The ancient Romans ate a cheese spread called moretum which may sometimes have been made with basil. The herb likely first came from North Africa.
Historically, pesto was (and is sometimes still) prepared in a marble mortar with wooden pestle.