a daughter. In her letters Sophia describes George as a responsible, conscientious child who set an example to his younger brothers and sisters. By 1675 George's eldest uncle had died without issue, but his remaining two uncles had married, putting George's inheritance in jeopardy, for his uncles' estates might pass to their own sons, were they to have any, instead of to George. George's father took him hunting and riding and introduced him to military matters; mindful of his uncertain future, Ernest Augustus took the fifteen-year-old George on campaign in the Franco-Dutch War with the deliberate purpose of testing and training his son in battle. In 1679 another uncle died unexpectedly without sons, and Ernest Augustus became reigning Duke of Calenberg-Göttingen, with his capital at Hanover. George's surviving uncle, George William of Celle, had married his mistress in order to legitimise his only daughter, Sophia Dorothea, but looked unlikely to have any further children. Under Salic law, where inheritance of territory was restricted to the male line, the succession of George and his brothers to the territories of their father and uncle now seemed secure. In 1682 the family agreed to adopt the principle of primogeniture, meaning George would inherit all the territory and not have to share it with his brothers. Marriage In the same year, George married Sophia Dorothea of Celle, the daughter of his uncle George William, thereby securing additional incomes that would have been outside Salic laws. This marriage of state was arranged primarily to ensure a healthy annual income, and assisted the eventual unification of Hanover and Celle. His mother at first opposed the marriage because she looked down on Sophia Dorothea's mother, Eleonore (who came from lower nobility), and because she was concerned by Sophia Dorothea's legitimated status. She was eventually won over by the advantages inherent in the marriage. In 1683, George and his brother Frederick Augustus served in the Great Turkish War at the Battle of Vienna, and Sophia Dorothea bore George a son, George Augustus. The following year, Frederick Augustus was informed of the adoption of primogeniture, meaning he would no longer receive part of his father's territory as he had expected. This led to a breach between Frederick Augustus and his father, and between the brothers, that lasted until his death in battle in 1690. With the imminent formation of a single Hanoverian state, and the Hanoverians' continuing contributions to