The miller's son who painted like a king 

Start with the family business. Harmen Gerritszoon van Rijn owned a share in a malt mill on a branch of the Rijn in Leiden, and his wife Neeltgen was a baker's daughter. This is a household of small property and steady work, comfortable enough to be ambitious. Their son Rembrandt, born in 1606, was sent to Latin school, and in 1620 his name appears in the register of the University of Leiden. Almost immediately it stops appearing. He had decided to become a painter, which in the Dutch Republic meant leaving the world of books for the world of guilds.

It is worth being precise about what that decision involved, because the romance of the artist as a lone genius arrived two centuries later. A painter's training was a contract. A boy went to live and work in a master's house, ground pigments, prepared panels, copied the master's compositions until he could produce them from memory, and paid for the privilege. Rembrandt spent roughly three years with the Leiden painter Jacob van Swanenburg, then about six months in Amsterdam with Pieter Lastman, a specialist in crowded biblical and mythological scenes. Six months is short. It suggests a student who took what he needed and left.

What he took was subject matter and staging. Lastman painted stories at their loudest moment, with gestures pitched to be read across a room. Rembrandt kept the storytelling instinct and quietly threw away the noise. By his early twenties he was back in Leiden, working in a shared studio, painting small panels of old men reading and apostles thinking, and above all painting his own face by candlelight in every expression he could hold: startled, laughing, scowling, indifferent.

Those early self-portraits are usually described as vanity or as convenient free modelling. They are better understood as practice. He was learning what a human face does when a single low light hits it, which is the technical foundation of everything he became famous for. A trade training gave him the habit of solving problems with materials, and the daily discipline of a workshop gave him thousands of hours in front of the one subject that never charged a fee.

By 1631 word had travelled. A dealer named Hendrick van Uylenburgh saw money in the young man from Leiden and offered him a base in Amsterdam, a city of merchants who wanted their faces on walls. Rembrandt took it.

The following year he was handed the commission that would make him, and he immediately broke the rules of the form.