Connie L. Beckett 
Kingmaker And The Scribe [EPUB ebook] 

In ancient Egypt, the venom of a strange, hooded serpent connects two souls.
Reincarnated over and over again, their fates are forever intertwined. In times of both war and peace, one is fated to be the maker of kings and the other the narrator of their shared history. Soon, the two will have to face the one inevitable thing in their existence: change.
From Egypt 2500 BC to medieval Scotland and hundreds of years into the future, the plot of this damnable play never changes.