“And afterward they desired a king: and God gave unto them Saul the son of Cis, a man of the tribe of Benjamin, by the space of forty years.”
King James Version (KJV)
13:21 He gave them Saul forty years - Including the time wherein Samuel judged Israel.
Ac 13:21 By the space of forty years. The Old Testament does not give the length of Saul's reign, but Josephus says Saul reigned for forty years.