When Was Pesto Invented?

Short answer
The earliest incarnation of what we recognise today as the precursor to pesto was invented by the Romans in the 1st century AD and called moretum. However, the first printed use of the word "pesto" can be traced to the late 1800s.

Long answer
The history of pesto is fascinating. The question of when the sauce was invented is a bit of a misnomer because it wasn't so much "invented" as developed and honed over many centuries. We can confidently say that the word "pesto" was published for the first time in 1863 when a recipe by Giovanni Battista Ratto appeared in the book La Cuciniera Genovese.

Mixing herbs, cheese, salt, and oil into a tasty paste can be traced back to Roman times when they enjoyed moretum sauce. The Genovese adapted this concept to utilise all the fantastic ingredients that grew in the hills around them.

The Sicilians did the same by including their world-class tomatoes and switching the pine nuts for almonds in a sauce we know today as Trapanese pesto. The French also have a version called pistou, which is practically identical to Genovese pesto but with a little more garlic and excluding pine nuts.

When you look into other cultures and cuisines, you'll discover plenty of sauces that contain many of the same ingredients as the classic basil pesto recipe, including romesco, chimichurri and salsa verde.