Which Russian royal guest was Rex formed to entertain in New Orleans?

Rex was formed to entertain Grand Duke Alexei during his 1872 visit to New Orleans.

The Russian grand duke, formally Alexei Alexandrovich, arrived during Carnival season as part of a tour of the United States. New Orleans businessmen organized the School of Design, the group that became the Rex Organization, to stage a grand daytime spectacle for the distinguished visitor while also attracting tourists and helping revive the city after the Civil War.

Alexei reviewed the inaugural Rex parade, and the visit helped establish traditions that remain associated with New Orleans Carnival. Rex means “king” in Latin, and the organization still presents the monarch known as the King of Carnival. The grand duke is often called “Grand Duke Alexis” in New Orleans sources. He is not the same person as Tsar Nicholas II, who was a later ruler of Russia and never the guest for whom Rex was created.