The flower island of Mainau is one of the most visited attractions on Lake Constance. There are very few travel groups that come to Lake Constance and do not stop off at the Mainau. The island also has an interesting history dating back to the Middle Ages.


The Teutonic Order

The first surviving documentary mention of Mainau dates back to the first half of the 13th century. At that time, the island belonged to Reichenau Monastery. Around 1265, the first knights of the Teutonic Order settled on Lake Constance. At first they had their seat at Sandegg Castle in Thurgau, then from 1271 on Mainau. In the course of time, further lands on the southern shore of Lake Überlingen came into the possession of the Order and the commandery (branch) of Mainau became one of the largest and most powerful in the bailiwick (administrative district) of Alsace-Burgundy.


Mainau in the possession of the Grand Duchy of Baden and the Swedish Royal Family

Due to secularisation, the Mainau fell to the Grand Duchy of Baden in 1806 and experienced several changes of ownership over the next decades. In 1853, Grand Duke Friedrich I of Baden finally bought the island and established his summer residence there. He also began to plant the island with rare and exotic trees and plants and had the first bridge to the mainland built. After his death, his son bequeathed the island to his sister Victoria, Queen of Sweden.

Victoria’s son transferred the administration of the island to his son Lennart Bernadotte in 1932, who had lost all his titles by marrying a commoner. Lennart Bernadotte left Sweden with his family and settled on Mainau. He soon began to restore and expand the island’s overgrown parks. The island was also opened to visitors.


History of the Mainau during the Second World War

Lennart Bernadotte and his family left Germany before the war began. The family spent the war years in Sweden. In 1943, Lennart Bernadotte leased the Mainau to the Organisation Todt, the construction organisation of the Ministry of Armaments. The plan was to build a recreation home here for armaments industrialists and for guests and employees of Albert Speer. In the end, however, nothing came of the rest home, because in 1944 the Foreign Office assigned the island to French collaborators under the leadership of Jaques Doriot. Doriot proclaimed the liberation of France from “Gaullist-Communist rule” from the Mainau. In February 1945, he was killed when his car was shot at by low-flying aircraft.


The Mainau under French occupation

After Doriot’s death, his followers fled and a reserve hospital was set up on the Mainau shortly before the end of the war. On 26 April 1945, Constance was occupied by French troops without a fight, and in May the French requisitioned the islands of Mainau and Reichenau to house French concentration camp prisoners from Dachau. 33 of them died on the Mainau, the others were returned to France in September 1945 and the military hospital was dissolved. Lennart Bernadotte returned to the Mainau in 1946 and the island was reopened to visitors in the same year.


The Isle of Flowers today

After the islands of Reichenau and Lindau, the Mainau is the third largest island in Lake Constance with an area of about 45 hectares and geographically belongs to Constance. It has been owned by the Lennart Bernadotte Foundation since 1974. The Mainau attracts many visitors every year with its variety of plants, the butterfly house and the beautiful baroque castle.


(D. F.)