Lee-Char, the Mon Calamari King, is pictured with his crown.
A crown is essentially an ornate head covering. Monarchs would don it as a symbol representing their power and authority. Furthermore, the term "crown" could also refer to the state or governing body that a monarch leads. On Onderon, the kings wore a crown that was a gilded headband, crafted to resemble interwoven foliage. The kings ruling Mon Cala possessed a crown shaped like a beehive, featuring a spiked band at its base. The Gungans' Bosses utilized a cone-shaped crown to signify their leadership, complete with a protective flap for the neck.
