Sodden was a former kingdom located around the Yaruga river between Cintra, Brugge, and Riverdell. After the Battle of Sodden Hill, Sodden was split into Upper Sodden and Lower Sodden, with the Yaruga forming a natural border. With the Peace of Cintra, the two halves were recombined into Sodden and it became a vassal state of Temeria.
In 1263, the Nilfgaardian Empire launched a full scale invasion of the north, and after slaughtering the kingdom of Cintra, moved its army to Sodden. The first battle of Sodden resulted in the northern army being swiftly defeated, and the Nilfgaardians conquering the region later known as Upper Sodden, before crossing the Yaruga and attacking the northernmost regions of Sodden, where they were defeated in the Battle of Sodden Hill. The defeat caused the Nilfgaardian Army to retreat back across the Yaruga, and no further battle insured as the other bank was too well defended by the northern armies.
The coat of arms for Sodden is not actually described in the novels. This particular coat of arms was designed by our resident heraldry and Witcher expert Mboro and was considered unofficial until they were used in The Witcher 3: Wild Hunt as part of Ciri's family tree image.