Phaya Sai Songkhram (Thai: พญาไสสงคราม) (also called Pu Saisongkhram) was a ruler of the historical Thai Kingdom of Sukhothai.[1] He became regent in 1298 upon sickness and death of his father, Ram Khamhaeng the Great, until his brother, Loe Thai ascended the throne upon his return from China.[citation needed]