The oldest rolling Mardi Gras parade in the current New Orleans Mardi Gras is the Krewe of Rex which first rolled in 1872.
Rex is known as the "King of Carnival" but should never be referred to as "King Rex" as "Rex" is Latin for "King" which would make saying "King Rex" redundant.
Purple, Green and Gold are the royal Mardi Gras colors and since 1892 have symbolized justice, faith and power respectively.
The Mystik Krewe of Comus was the first organized parade in New Orleans to roll with floats and it first rolled out in 1857.
"If Ever I Cease To Love" by singer Lydia Thompson is the official royal anthem of the New Orleans Mardi Gras and has been so since 1872.