6:21

his birthday: This event likely occurred at Herod Antipas’ residence in Tiberias, a city located on the western shore of the Sea of Galilee. One reason for this conclusion is that Mark here states that the most prominent men of Galilee were in attendance. (See study notes on Mt 14:3, 6.) The Bible mentions just two birthday celebrations​—the one referred to here, at which John was beheaded; the other, that of a Pharaoh, at which the Egyptian monarch’s chief baker was executed. (Ge 40:18-22) These two accounts are similar in that both occasions were marked with great feasting and the granting of favors, and both are remembered for executions.

military commanders: The Greek term khi·liʹar·khos (chiliarch) literally means “ruler of a thousand,” that is, soldiers. It refers to a Roman military tribune. There were six tribunes in each Roman legion. The legion, however, was not divided into six different commands; rather, each tribune commanded the whole legion for one sixth of the time. Such a military commander had great authority, including the power to nominate and assign centurions. The Greek word could also refer to high-ranking military officers in general. In the presence of such men of rank, Herod felt compelled to keep his oath and therefore ordered the beheading of John the Baptizer.