Was King Herod married before he married Herodias?

Yes, Herod Antipas B.C. 4 - A.D. 39 was first married to the daughter of Aretas, an Arabian king of Petraea. Antipas was intrigued with Herodias, the wife of his half-brother, Philip I. Antipas and Herodias eloped and wed even though each were still married to their spouses.