This information has come to me as webmaster:

"The origin of the Coat of Arms on this webpage is not revealed in the book on the Hagerup family published in Copenhagen in 1905.

The Christian cross at the peak symbolizes direct decendants from Jesus Christ. 

The shield of two parts, - symbolize that the family was divided when the Coat of Arms was designed, into two families, - one part that defended the Christian Faith (a Bishop or a Pope) and one of Royal Decent (King or Duke)."