Work on the extension to the royal burial chamber in the catacombs of the Nieuwe Kerk in Delft has uncovered some 200 skeletons.

After months of digging, archaeologists have now reached a depth of 1.5 metres. ‘We have now found 150 people in ‘proper’ graves and the bones of four to five people buried together in various charnel repositories,’ archaeologist Michael Bot told local broadcaster Omroep West.

City archaeologist Steven Jongma said the find added ‘a new chapter to the history of the church. ‘We are discovering big differences between the medieval bones we found earlier on the Markt (the square on which the church stands) and the people we’re finding in the church,’ he said.

The Markt was a medieval burying ground for the poor whereas the church accommodated the rich burghers of Delft.

Outside the church people were buried a lot closer together and in cheap coffins, Jongma said. Their physical condition was also notably worse and they died younger than their well-heeled counterparts.

Archive and DNA research will have to show who the people in the graves are. ‘That will make it extra interesting because then we will be able to link a profession and a life story to the city,’ Jongma said.

The royal burial chamber is currently home to 43 members of the Dutch royal family dating back to William of Orange in the 16th century. The extension will cost some €4m and is being paid for by the state.