Roger de Flor (c. 1267 – 30 April 1305), also known as Ruggero/Ruggiero da Fiore or Rutger von Blum or Ruggero Flores, was an Italian military adventurer and condottiere active in Aragonese Sicily, Italy, and the Byzantine Empire.

When the Peace of Caltabellotta brought the war to an end in 1302, Frederick was unwilling and unable to keep a mercenary army and was anxious to free the island from troops (called "Almogavars"), whom he no longer had the means of paying.

Given the political and military situation, Roger found an opportunity to make his services useful in the East fighting the Ottoman Turks, who were ravaging the Byzantine Empire.

[2] He was adopted into the imperial family, married to the emperor's niece Maria Asenina (daughter of Ivan Asen III of Bulgaria),[3] and made grand duke (megas doux) and commander-in-chief of the army and the fleet.

The life of Roger de Flor inspired the fictional character of Tirant lo Blanc, an epic romance written by Joanot Martorell, published in Valencia in 1490.

It is one of the best-known medieval works of literature in the Catalan language and played an important role in the evolution of the Western novel thanks to its influence on Miguel de Cervantes.

Roger de Flor is one of the main characters of The Horsemen of Death ("Surma ratsanikud"; 1963), a historical novel by Estonian writer Karl Ristikivi.