First Battle of Varna

(Not to be confused with the battle that took place during the Great Mediterranean War; that was the Second Battle of Varna.)
The First Battle of Varna is the opening scene of Episode I ("Failure") of Brazilian Mapping's Alternate History of Europe series.
This battle actually occurred during the Crusade of Varna, however in real history it was the Ottomans who won the battle. The series is based on the opposite outcome, where Poland was victorious.