This could suggest that his painting of the Last Supper in Dordrecht is (based on) a period group portrait of basket weavers and barrel makers, since this painting was commissioned for the altar of St John the Evangelist in the Grote Kerk, Dordrecht, and at that time (c. 1560) St John was the patron saint of the coopers.
[citation needed] Karel van Mander goes on to say that while Key was painting Fernando Álvarez de Toledo, Duke of Alba's portrait, he pretended he could not understand foreign speech, and so he overheard the Bloed-raedt plot against the statesmen Lamoral, Count of Egmont and Philip de Montmorency, Count of Hoorn.
When these men were executed on the main square in Brussels on 5 June 1568, he was so upset that he died on the same day, in Antwerp.
This story was widely accepted as the truth, but van Mander found it hard to believe and thinks he died a few days beforehand.
The surviving last supper is still in the original frame with a Latin inscription around it with the words of Luke 22:21-23 which are translated as: But, behold, the hand of him that betrayeth me [is] with me on the table.