King Carl Gustaf seems to be a humble monarch - he leaves all towns and fortresses to his vassals while granting himself a mere castle - despite having the power to own the capital city like most rulers would do, especially in Mount&Blade and Warband.
He is based on a real person who ruled Sweden from 1654-1660.
Although his name was King Charles X Gustav of Sweden, he was actually the fourth King Charles - this is because his grandfather, King Charles IX, chose his numeral from a fictional history of Sweden.
He was a member of a branch of the House of Wittelsbach, a prominent Northern European noble house.
Johann Koster, a doctor for the king, mistook his pneumonia contracted by traveling throughout the kingdom with a cold for scorbut and dyspepsia. The pneumonia then evolved into a sepsis, which caused his death on February 13, 1660, at the age of 37.