French-Canadian explorer Pierre Le Moyne d’Iberville and his men sailed up from the Mississippi River’s mouth and pitched camp 60 miles south of the future site of New Orleans.

The date was March 3, 1699, and Mardi Gras was being celebrated in Paris. Perhaps feeling a little whimsical, Iberville named the spot “Point du Mardi Gras” and christened the adjoining channel “Bayou du Mardi Gras.” And so began a centuries-long collaboration between the city’s most storied waterway and the city’s most storied celebration.

Starting in 1874, Rex made his ceremonial Lundi Gras entry at the foot of Canal Street on legendary steamboats such as the Robert E. Lee. Assuming the likeness of such historical figures as Louis XIV, Charles II and Charlemagne, he mounted a carriage and led a military parade that stopped at Gallier Hall, where he received keys to the city.

When the World’s Industrial and Cotton Centennial Exposition was held in Audubon Park in 1884, Rex made his appearance via the steamer Edward Richardson. An 18-vessel naval parade brought up the rear.

The annual river arrival of Rex remained popular until 1917, when World War I canceled Carnival. The custom was not resumed when parades returned in 1920.

In 1933, the Algiers-based Krewe of Alla began a new tradition of having its king and his entourage arrive by river aboard a yacht. The custom continued until World War II.

The West Bank Krewe of Choctaw, founded in 1935, joined the river-arrival fraternity in 1946 when Chief Choctaw John Beninate Sr. sailed the Mississippi in a salute to the returning heroes of WWII. In 1963, the men of Choctaw staged a Carnival ball for sailors aboard the aircraft carrier USS Lexington, which was anchored in the river. Choctaw continues its river parade to this day. This year’s procession was presented Feb. 8 aboard the Creole Queen.

In 1987, a new custom was born with the inaugural Lundi Gras celebration at the Riverwalk. A highlight of the annual event is the river arrival of Rex aboard a Coast Guard cutter.

The Krewe of Zulu joined the Mississippi River celebration in 1995, when its royalty made a Lundi Gras landing at Woldenberg Park. In the 1940s, Zulu and his entourage arrived aboard oyster luggers that sailed up the New Basin Canal.

In the early 20th century, Southern Pacific’s Atlantic Line included three New Orleans-based steamships named after Carnival krewes — the S.S. Momus, S.S. Comus and S.S. Proteus. Long ago, the ships retired from the river, but you never know when some enterprising krewe might decide to add an exciting new superfloat to its repertoire.