result of the Protestant Reformation, there is no dominant religion in Westphalia. Catholicism and Lutheranism are on relatively equal footing. Lutheranism is strong in the eastern and northern parts with numerous free churches. Münster and especially Paderborn are thought of as Catholic. Osnabrück is divided almost equally between Catholicism and Protestantism. After the defeat of the Prussian Army at the Battle of Jena-Auerstedt, the Treaty of Tilsit in 1807 made the Westphalian territories part of the Kingdom of Westphalia from 1807 to 1813. It was founded by Napoleon and was a French vassal state. This state only shared the name with the historical region; it contained only a relatively small part of Westphalia, consisting instead mostly of Hessian and Eastphalian regions. After the Congress of Vienna, the Kingdom of Prussia received a large amount of territory in the Westphalian region and created the province of Westphalia in 1815. The northernmost portions of the former kingdom, including the town of Osnabrück, had become part of the states of Hanover and Oldenburg. Flags and coat of arms The flag of North Rhine-Westphalia is green-white-red with the combined coats of arms of the Rhineland (white line before green background, symbolizing the river Rhine), Westfalen (the white horse) and Lippe (the red rose). After the establishment of North Rhine-Westphalia in 1946, the tricolor was first introduced in 1948, but was not formally adopted until 1953. The plain variant of the tricolor is considered the civil flag and state ensign, while government authorities use the state flag (Landesdienstflagge) which is defaced with the state's coat of arms. The state ensign can easily be mistaken for a distressed flag of Hungary, as well as the former national flag of Iran (1964–1980). The same flag was used by the Rhenish Republic (1923–1924) as a symbol of independence and freedom. According to legend, the horse in the Westphalian coat of arms is the horse that the Saxon leader Widukind rode after his baptism. Other theories attribute the horse to Henry the Lion. Some connect it with the Germanic rulers Hengist and Horsa. Geography North Rhine-Westphalia encompasses the plains of the Lower Rhine region and parts of the Central Uplands (die Mittelgebirge) up to the gorge of Porta Westfalica. The state covers an area of and shares borders with Belgium (Wallonia) in the southwest and the Netherlands (Limburg, Gelderland and Overijssel) in the west and northwest. It has borders