Duke Conrad was the leader of the countries which surrounded the city-state of Varuz. Described by Clara Oswald as a "calculating, almost predatory" figure, Conrad was fiercely determined to invade and conquer Varuz, and seize control from Duke Aurelian in the process.
Unlike the Dukes and Duchesses of Varuz, Conrad was elected as ruler by the vote of the common people; in his view, this made him morally superior to Aurelian and Guena, his counterparts in Varuz. The countries which Conrad controlled had, in the past, long been controlled by Varuz; after becoming a Duke, he became obsessed with restoring the sovereignty and independence of his nations.
By the time of the Twelfth Doctor and Clara Oswald's arrival in Varuz, Conrad's invasion was well underway, and he had a vanguard camped in the mountains at the country's border. Conrad sent a group of ambassadors to treat with Aurelian, hoping that Varuz would surrender peacefully, but they never returned. He later learned from Clara and Emfil that they had been murdered on their journey, possibly by bandits in the mountains. When Clara, Emfil and Mikhail arrived at his camp, following their banishment from Varuz, Conrad agreed to shelter them in exchange for information. Conrad eventually persuaded Mikhail to join his efforts in the invasion.
Conrad's army, led by Mikhail, marched on Varuz from the mountains during the time of Lancelot's quest for the Glamour, hoping for a bloodless conquest. Unfortunately, both Lancelot's company and Aurelian's knights were waiting for the invading force, and so a battle commenced. Conrad stayed well away from the forefront of the battle, allowing Mikhail to lead his troops and slay Aurelian in combat.