How do we know when these pictures date from?
The portraits of Edward VI in the collection at the National Portrait Gallery were all analysed using dendrochronology. This technique of tree-ring dating can be used to help date panel paintings on wood. It can provide a date after which a tree was felled and estimate possible usage. This is very useful when thinking about which version of a portrait was made first and which others are later copies. Both the profile portrait (below left) and the full length (below right) were shown to have been painted in Edward's lifetime. The wood used for the panel of the profile portrait revealed that it is derived from a tree which was felled sometime after 1529. Similarly, the panel for the full length revealed the wood is from a tree which cannot have been felled before 1530.
King Edward VI
by Unknown artist, after William Scrots
circa 1546
NPG 442
King Edward VI
by Workshop associated with 'Master John'
circa 1547
NPG 5511
Two of the boards that were used to make the full length panel have extremely interesting marks on the back of the panel. These are almost certainly cargo, merchant or quality marks inscribed into the wood before it was transported by ship to England (see arrow shape at bottom centre). Tudor port books recording imports travelling into the UK by sea reveal that vast quantities of oak timber was imported from the Baltic regions. Some of this wood was used by artists for panel paintings.