The identity of the subject has long been recognised from physiognomic matches and the Order of the Dragon emblem on the breast. Pisanello may have met Sigismund in 1433 in Ferrara or Matnova, when the king travelled to Italy for his coronation as Holy Roman Emperor. The age of the figure in the drawing also corresponds to the then 60-year old Sigismund. A papal letter of safe passage of 1432 suggests the possibility that Pisanello was sent north from Rome partly for the very purpose of making a portrait of the Emperor, who was resident there. The profile setting derives from the ancient numismatic tradition and is one of the earliest of that form from the era. The portrait may have been intended by Pisanello as a precursor to a painting. Although the highly detailed execution might suggest otherwise, the notes in the top right corner and in front of the beard specifying the colours for some of the details are clear evidence in favour of this hypothesis.