First mentioned in chapter 910, when Aqua Rose suggested Shi Feng to considering Purple Thorns Kingdom as alternative for Zero WIng's development after the abyssal monsters arise in the Twin Towers Kingdom.
Purple Thorns Kingdom was one of the many kingdoms situated on the God's Domain main continent. It is located close to Star-Moon Kingdom. It was known to be a herb-rich country with many low tier and rarer high tier materials available in their maps. However the kingdom perished after a horde of monsters mysteriously emerged within the kingdom. 
News of Its Destruction in chapter 2650