the covering thrown over a coffin, is the Latin pallium, a square piece of cloth used by the Romans to throw over their
shoulders, or to cover them in bed; hence a coverlet.
the long sweeping robe, is the Roman palla,
worn only by
princes and women of honest fame. This differed greatly from the pallium
, which was worn by freemen and slaves, soldiers, and
Sometimes let gorgeous Tragedy
In sceptred pall come sweeping by.
Milton: Il Peuseroso
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894