In heraldry nine crowns are recognised: The oriental, the
triumphal or imperial, the diadem, the obsidional crown, the civic, the
crown vallery, the mural crown, the naval, and the crown celestial.
The blockade crown
(corona obsidionalis), presented by the Romans to the
general who liberated a beleaguered army. This was made of grass and
wild flowers gathered from the spot.
A camp crown
was given by the Romans to him who first forced his way into the
enemy's camp. It was made of gold, and decorated with palisades.
A civic crown
was presented to him who preserved the life of a civis or
Roman citizen in battle. This crown was made of oak leaves, and bore
the inscription, H.O.C.S. —i.e. hostem occidit, civem servavit (a
foe he slew, a citizen saved).
A mural crown
was given by the Romans to that man who first scaled the wall of a
besieged town. It was made of gold and decorated with battlements.
A naval crown
was by the Romans given to him who won a naval victory. It was made
of gold, and decorated with the beaks of ships.
An olive crown
was by the Romans given to those who distinguished themselves in
battle in some way not specially mentioned in other clauses.
An ovation crown
) was by the Romans given to the general who vanquished pirates or
any despised enemy. It was made of myrtle.
A triumphal crown
was by the Romans given to the general who obtained a triumph. It
was made of laurel or bay leaves. Sometimes a massive gold crown was
given to a victorious general. (See Laurel.)
The iron crown of Lombardy
is the crown of the ancient Longobardic kings. It is now at Monza,
Henry of Luxembourg and succeeding kings were crowned with it.
Napoleon I. put it on his head with his own hands. It is a thin fillet
of iron, said to be hammered from a nail of the true cross, covered
with a gold circle, enamelled with jewels, etc.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894