The first recorded mention of Holligen is in 1257, when it was owned by the Teutonic Knights commandry of Köniz. It is likely that there was a castle here to control the Bümpliz-Köniz road and administer the estates. However, very little is known of this building. The current castle was built around 1500 by the Bernese Schultheiss Wilhelm von Diesbach. It was built in the style of a typical Burgundian castle, with a square donjon of massive stone blocks with four towers at the corners. A residential hall with a staircase tower was added around 1575 for Peter von Graffenried.
A map by Thomas Schöpf from 1577 and a city plan from 1623/24 both show the castle surrounded by a ring wall with several small towers. Between the 1624 plan and 1667, the square castle was expanded with the construction and expansion of the residential hall to the west. In the 18th century the castle was renovated in the Baroque style. The facade and windows were redone in 1765.
Between 1991-1994 the castle was extensively renovated and repaired. Today it is owned by the Turmstiftung Schloss Holligen, a foundation that maintains the castle.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.