Queen Sophie of Sweden, daughter of Duke Wilhelm of Nassau and Princess Pauline von Württemberg, spent 10 longer holidays in Bad Honnef, several of which at Villa Thelen in the period 1896-1899. In 1900, Franciscan nuns from Nonnenwerth – a convent on an island in the Rhine – acquired the estate in the centre of the city to use it as a collegiate girls‘ school which opened the doors on October 15 of the same year.
Three years after the end of World War II (1940-45) the first Belgian secondary school in Germa ny was accomodated in the then abandoned villa near the Rhine. The lessons for children of the Belgian occupation army in Germany started on September 15, 1948.
202 students (122 francophones and 80 dutch/flemish) visited the first year. They were instructed by 24 mainly billingual teachers directed by Paul Sak.
The school was officially inaugurated in November by Kamiel Huysmans, Minister for Arts and Science, colonel Raoul Defraiteur, Minister of National Defense and three-star general Jean-Baptiste Piron, commander-in-chief of the Belgian troops in Germany.
1949 the status Koninklijk Atheneum/Athénée Royale Bad Honnef was retroactively conferred to the institution.
On May 23, 1949 the german Basic Law (Grundgesetz) was officially announced by Konrad Adenauer, president of the Parliamentary Council. Bonn was elected to be the capital of RFG and became a neutral zone. Therefore the first Belgian gymnasium in Germany had to leave Bad Honnef by the end of December 1949. Haus Venauen in Rösrath, a castle built in 1555 by Peter von Bellinkhusen, was chosen as the new location. However, the classrooms of the former school (1938-1945) of National Socialist Public Welfare (Nationalsozialistische Volkswohlfahrt) wern’t yet ready for occupancy as they still had to be renovated. So the school was temporarily lodged in blocs of the „Hardings Barrack“ in Wuppertal. The lessons there started in January 1950. Three months later, in April 1950, the renovation works in Rösrath were completed. Without any regret teachers and students moved to their new permanent location at the Sülz called Koninklijk Atheneum/Athénée Royale Rösrath (KAR/ARR) where they stayed until 2003*.
Today Villa Thelen at Bismarckstrasse 12-14 in Bad Honnef – meanwhile substanstially enlarged – belongs to the Archbishopric of Cologne. It accomodates St. Josef Realschule, a middle school for ages 10-16.
*The flemish students moved to Bensberg in 1965. For shortage of students Koninklijk Atheneum Bensberg/KAB was closed in 1999. The remaining students returned to Rösrath.
1970 a third flemish secondary school was established in Soest (Rijksmiddelbare School/RS – Koninklijk Atheneum Soest/KAS). The school which was originally accomodated at Adam Kazerne then at the abandoned Canadian Soest Senior School, was closed on June 30, 1994.