Why was king Herod interested in finding the new king?

King Herod was interested in finding the new king, often identified as Jesus, because he saw this figure as a potential threat to his own power and rule. The arrival of the "King of the Jews," as prophesied, posed a challenge to Herod's authority and could incite rebellion among the people. Driven by paranoia and the desire to maintain his throne, Herod sought to eliminate this threat by searching for the newborn king, ultimately leading to the infamous Massacre of the Innocents.