North Korean leader Kim Jong Un shares a family trait with his father and grandfather: a penchant for purges to hold onto absolute power.

Since the reclusive nuclear nation's founding in 1948, the Kims have eliminated people perceived as a threat to their cult of personality. Charges have ranged from spying for the U.S. to gossiping about a leader's mistress.

"North Korea's history is a history of purges," Oh Gyeong Seob, a North Korea researcher at the Sejong Institute near Seoul, said by phone. "And purges are increasing in frequency under Kim Jong Un. It's a sign he is resorting to the politics of fear to cope with his sense of insecurity."