|Title||Maester at Whitewalls|
|Book||The Mystery Knight (appears)|
Lothar was the maester at Whitewalls during the reign of King Aerys I Targaryen.
Lothar was stooped and old. He had long hair and his face was lined and aged with a large nose.
During the wedding tourney at Whitewalls, Lothar took care of the parade of wounded, among them Ser Duncan the Tall. While in his care he let Duncan know of his disdain for the martial arts.
After Duncan lost his armor and horse to Ser Uthor Underleaf, Duncan's squire, Prince Aegon Targaryen, went to Lothar and showed him the dragon ring that had been given to him by his father, Prince Maekar Targaryen, hoping to enlist Lothar's help in sending a raven for help. However, Lothar delivered the Targaryen prince to Lord Ambrose Butterwell upon seeing the ring.