Written in 1957, George R.R. Martin calls this series "The original Game of Thrones." How right it he is. The story covers the French Monarchy (Capetian dynasty) in the 14th century. The series begins as the French king Philip the Fair, already surrounded by scandal and intrigue, brings a curse upon his family when he persecutes the Knights Templar.  The medieval folk were very superstitious, and wholly believed it was the curse that caused all the chaos-never thinking it was the poor choices of the King that were installed. 

This was the fourth in the series, and it deals with the suspicious deaths of two kings and the passing over of the direct heir to the throne, a woman. 

I am not sure that continuing is a good idea (though I will) as the 7th and final book was never translated from French. I suppose I will just have to read a non-fiction book to find out what happened.