It’s Lundi Gras, when you can watch the monarchs of both Zulu and Rex arrive at the Riverwalk and then catch back-to-back parades that span two centuries of parading history.

Rolling first in New Orleans is one of the season’s prettiest parades — also one of the oldest and smallest. Setting out at 5:15 p.m., the 230 men of Proteus will be led by the captain on horseback, followed by 34 riding lieutenants and 30 flambeaux. The riderless horse in front of the parade will be in memory of former captain and civic leader Beau Bassich, who died last summer.

The 20-float procession, the club’s 112th, is titled “The Hindu Heavens.” Royal Artists constructed the floats on chassis that date from the 1880s. The identity of the gentleman who portrays Proteus is never revealed to the public, but his magnificent seashell float is a thing of beauty.

Try to catch one of the season’s neatest throws, the Proteus plush LED flambeaux.

Following Proteus is Orpheus, the Carnival club that Harry Connick Jr. helped organize 23 years ago. The 2016 theme is “The Wizard’s Bestiary.” The krewe of 1,300 male and female members will ride 38 floats. Legendary among them are the “Trojan Horse,” “Leviathan,” “Dolly Trolley” and the ever-expanding eight-unit “Smokey Mary” tandem float, which holds 230 riders.

The Chariots of Orpheus will again appear, along with 60 original flambeaux. This year’s most collectible throws are Smokey Mary beads and hats and special 2 ½-inch doubloons that salute the late musical legend Frankie Ford. Other neat throws include Leviathan LED hats and Orpheus face masks.

Nathan Fillion from the ABC series “Castle” will reign as monarch. The parade ends inside the Morial Convention Center, where the Orpheuscapade is celebrated.

At 7 p.m. in Metairie, a new krewe with an old name, Pandora, debuts. This all-female krewe spun off from Nyx in New Orleans. It plans a 17-float parade and will unveil glitter-covered boxes as the members’ signature throw.

In recent years, Monday night has not been a lucky one for parades in Jefferson Parish. After Metairie’s oldest parade, Zeus, went belly-up, parade permits for Monday night were issued to the Krewes of Hera and Atlantis, neither of which actually mounted a parade.