de Shrekwiki :
In Shrek The Musical, Farquaad's past is revealed during the musical number "The Ballad of Farquaad". Farquaad's mother was revealed to be a Princess named Pea from the Princess and the Pea and his father being Grumpy (which explains his comically short stature) from Snow White. They married for love, and his mother was apparently disinherited from her crown.
Quanto ao conto de fadas, é um conto e não menciona nomes (personagens ou reinos): A Princesa e a ervilha