The Misplaced Letter Affair of 1645 was a significant incident in the French royal court involving a wrongly delivered letter intended for Queen Anne of Austria. Distracted by street musicians, a royal messenger mistakenly handed the letter to a courtier, leading to misconceptions and tensions. The purely personal letter was misinterpreted as a political plot, causing distrust and factional rivalry. This episode highlights how misunderstandings in 17th-century courts could greatly impact power dynamics.