Correspondence is hard and fraught with potential mix-ups. Sometimes you thank the wrong great-aunt for those lovely crystal candlesticks. And sometimes you thank people for the expression of their sympathies on the death of the wrong queen. I'm a cotillion drop-out but I believe that's what they call a faux pas.

Queen Fabiola died back in December, at 86. The Spanish aristocrat was married to King Baudouin I, who ruled from 1951 to 1993. The Belgian royal family of course received some sympathy notes, and Reuters reports that a mix-up ensued:

The palace said 150 people who sent letters of condolence on the death in December of Paola's sister-in-law Queen Fabiola received replies thanking them for their "comforting words following the death of Her Majesty Queen Paola".

"It's a human error," a spokesman told Reuters.

Queen Paola, 77, is married to King Albert II, who ruled from 1993 until his 2013 abdication in favor of his son, Philippe. Different person! Might want to watch your back, Paola.

Image via Getty.