Therefore Søbygaard is often dated around 1580. In the late 1570s, the Duke had built the manor of Gråsten in the eastern part of Ærø, and after 1600 the manor Gudsgave west of Marstal was built.


Duke Hans the Younger inherited Ærø in 1564. However, he did not take over the island until 1571 when his mother died, but the land around Søbygaard remained under the Danish King as the area was old church land, and Ærø, just like Als, was part of the Funen diocese, even though both islands were under the Duchy of Slesvig.

Hans the Younger was very keen to get his hands on the land of Søbygaard, and in 1579 he succeeded. Around this time, he started building the main manor house with the farm buildings and an impressive moat.

In a letter from 1609, Hans the Younger wrote that approx. 30 years ago he had started building Søbygaard.