Edmund met and married Harper when they were still young, a match of convenience, not love. She was wealthy, and he was an heir to the Claus family fortune. They did eventually fall in love, and had two children, Luna and Alec.
Luna was murdered when she was 10, and the 5 year old Alec was never the same again. Edmund and Harper never recovered from losing their daughter, and could not give their remaining child the love and affection he needed.
Edmund pushed himself into running their estate, while Harper gladly took the Claus seat on the High Council so she wouldn't have to be at home.
The couple still love each other, but their relationship is almost non-existent.