from
Easton's 1897 Bible Dictionary
Aretas
the father-in-law of Herod Antipas, and king of Arabia Petraea.
His daughter returned to him on the occasion of her husband's
entering into an adulterous alliance with Herodias, the wife of
Herod-Philip, his half-brother (Luke 3:19, 20; Mark 6:17; Matt.
14:3). This led to a war between Aretas and Herod Antipas.
Herod's army was wholly destroyed (A.D. 36). Aretas, taking
advantage of the complications of the times on account of the
death of the Emperor Tiberius (A.D. 37), took possession of
Damascus (2 Cor. 11:32; comp. Acts 9:25). At this time Paul
returned to Damascus from Arabia.