[Lanhoso Castle](https://en.wikipedia.org/wiki/Castle_of_Lanhoso) was an important line of defense, protecting Portugal against the influnce of the Kingdom of Leon (spanish kingdom). In the 12th century, Theresa Queen of Portugal was besieged in this castle, as she rebelled against her half sister. Portugal had vassalic ties with the crown of Leon. She lost the battle and Portugal remained a vassal state. She allied with noblemen of Galicia (another spanish kingdom) which displeased the Portugese court. Because of that she was later ordered to be imprisoned in the tower of the Lanhoso castle, by her son. From the castle, only the tower remains. The cause of this destruction was the great great grand father of the famous portugese general, saint constable, who burned the castle down, as he found out that his wife cheated on him there. The fire killed the lovers, servants and the life stocks. The castle was abonded as it lost its strategical importance. https://youtu.be/65pIMQu9UhE