I was trying to recall and find information on the specific hat of Richard I that was ruined by William des Barres in a mock joust/ tournament at Messina. While digging around for the information I read the following about Caps of Maintenance.
“A cap of maintenance was worn under the crown by the monarch from early Norman times and he to whom the right was granted need doff his cap to nobody. It was therefore a significant mark of royal approval. A cap and a sword were traditional items in a mayor's regalia.”

Anyhow, caps of maintenance are mentioned in the context of being used by Templars, and others. In some cases, it sounds as if they were also caps worn over helmets to affix heraldic plumes.

Does anyone have some great examples of these?
http://www.myArmoury.com/talk/viewtopic.php?t=5265

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