Double Portrait of Isaac Pontanus and Hendrik van Beek

Hendrik van Beek was born on 29 February 1680, a leap day, so he had a real birthday only once every four years. On 29 February 1688, when he turned eight, his grandfather Isaac Pontanus gave him a gold medal. Pontanus was a minister of the Remonstrants, the Protestant group pushed out of the official Reformed Church in 1619. The Latin text on the medal carefully records that this birthday came after the second four-year wait.

A year later Van Musscher painted the gift on a round metal plate only 9 centimetres across, the same size as the medal. The grandfather, in a purple coat and white preaching bands, hands it over with one hand and rests the other on the boy's shoulder. In 1720 the boy's aunts left the little picture to the Remonstrant church in Rotterdam. It was stolen from there in 1981, turned up again with an Amsterdam dealer, and in 2008 came to the Rijksmuseum, which also owns the medal.