From AG Jeans + Buttero collaboration press release:

About Buttero

Similar to AG, where father and sons work side-by-side, Buttero is a family affair. The calzature was founded in 1974 by Mauro Sani in Tuscany, Italy, and is now run by Mauro and his three sons. Buttero originally set out to make unrivaled riding boots utilizing the honored traditions of Italian shoemaking. Now, craftsmen churn out footwear for men and women that is 101% handcrafted fusing rawness and elegance. Buttero’s quality is best experienced when you first open the shoe box and inhale the perfume of Tuscan vegetable-tanned hides produced the old fashioned way, with passion and love.