Willem van Aelst was born in Delft, where he trained as a still life painter with his uncle, Evert van Aelst. He completed his apprenticeship by 1643, at which time he enrolled in Delft's Guild of St Luke. In 1645 he was documented in France, and in 1649 he was working in Florence as court painter to the Grand Duke of Tuscany, Ferdinando II de' Medici. At the Medici court Willem befriended a fellow Dutch still-life painter, Otto Marseus van Schrieck, whose smooth, detailed style influenced the young artist. In 1656 van Aelst returned to the Dutch Republic and settled in Amsterdam, where he established a successful career as a painter of ornate, brightly colored still lifes of unparalleled surface detail. Among his most accomplished pupils in that city was Rachel Ruysch.