Following on from my previous post I have found a view of part of Andrea di Firenze's The Way of Salvation which shows some of the figures of the ecclesiastical and temporal hierarchy in more detail, including the figure of the Knight of the Garter, who is very prominent in the centre foreground. Ages ago I read a piece which tried to identify him, but have not got it to hand.
Here are two more details:
The first shows the figures to the left of the previous group, with members of various religious orders and a bishop:
The Dominicans preaching:
Images: arthistory390 on Flickr
Finally, here is a detail from the upper right of the painting: