It’s a medieval country. Maybe biblical, think David didn’t deal with rivals likewise?
Churchill’s History of the English Speaking Peoples is filled with this stuff.
The royals of Middle Ages England were every bit as brutal at eliminating rivals.
Solomon outdoes his father, David, in getting rid of enemies. (Bathsheba was Solomon’s mom.)
The blood really flows in II Kings. Of the 44 kings for Judah and the northern kingdom, only 2 were great and 2 were okay.