He is first recorded in Hamburg in 1367, and lived there for the rest of his life, becoming a citizen and Master in 1376, and achieving considerable prosperity.
His most famous surviving work is the large Grabow Altarpiece (or Petri-Altar) in the Kunsthalle Hamburg, the largest and most important North German painting of the period.
A sculpture group depicting Saint Christopher by his hand is located in Falsterbo Church, Sweden.
[3] His style is less emotional than that of his Hamburg near-contemporary Master Francke, but has great charm.
Bertram was largely forgotten after the Renaissance until the end of the 19th century when, like Master Francke, he was rediscovered and published by Alfred Lichtwark, director of the Hamburg Kunsthalle.