[Emblem of the city of Madrid]

EN ESTA PLAZA HIRIÓ MORTALMENTE
FRANCISCO DE QUEVEDO
A UN CABALLERO EL JUEVES SANTO DE 1611 EN DEFENSA DE UNA DAMA

The plaque is found in the square where in 1611 when praying in the Church of San Martin, the Spanish politician, poet and writer Francisco de Quevedo (1645-1580) saw a woman being slapped by another man. Da Quevedo challenged the man to a duel, fatally wounding him and the opponent subsequently died of his wounds.

The place where the sign is located was photographed on the same day by the same photographer Click for a larger image

It seems that the plaque says that de Quevedo was mortally wounded, but that was not the case, especially in light of the fact that he died in 1645.

Translation of the text on the sign:
IN THIS SQUARE HE WAS DEADLY WOUNDED

FRANCISCO DE QUEVEDO
TO A GENTLEMEN ON HOLY THURSDAY 1611 IN DEFENSE OF A LADY