John the Baptist was the son of a Priest, a Cohen, and his father was Zachariah, so his proper name was not ‘John the Baptist', but Johanan Bar Zachariah Cohen.
The Gospel of Mark 6:17-28 gives us this account:
"For Herod himself had sent and laid hold of John, and bound him in prison for the sake of Herodias, his brother Philip's wife; for he had married her. Because John had said to Herod, "It is not lawful for you to have your brother's wife." Therefore Herodias held it against him and wanted to kill him, but she could not; for Herod feared John, knowing that he was a just and holy man, and he protected him. And when he heard him, he did many things, and heard him gladly. Then an opportune day came when Herod on his birthday gave a feast for his nobles, the high officers, and the chief men of Galilee. And when Herodias' daughter herself came in and danced, and pleased Herod and those who sat with him, the king said to the girl, "Ask me whatever you want, and I will give it to you." He also swore to her, "Whatever you ask me, I will give you, up to half my kingdom." So she went out and said to her mother, "What shall I ask?" And she said, "The head of John the Baptist!" Immediately she came in with haste to the king and asked, saying, "I want you to give me at once the head of John the Baptist on a platter." And the king was exceedingly sorry; yet, because of the oaths and because of those who sat with him, he did not want to refuse her. Immediately the king sent an executioner and commanded his head to be brought. And he went and beheaded him in prison, brought his head on a platter, and gave it to the girl; and the girl gave it to her mother." - NKJV.
Herod Antipas II, (also known as Herod the Tetrarch) was the son of Herod the Great by Malthake, a Samaritan.
He first married a daughter of Aretas, "King of Arabia Petraea," but afterward sent her back to her father, and took Herodias, the wife of his half-brother, Herod Philip as his wife.
Now King Aretas of the City/State of Damascus, at the time of the death of John the Baptist, was still living at the time of Paul's conversion.
"In Damascus the governor, under Aretas the king was guarding the city of the Damascenes with a garrison,desiring to arrest me;" 2 Corinthians 11:32
According to Microsoft Encarta 2002 on the Subject of Damascus:-
"Damascus has more than 200 mosques, of which 70 are still in use. Of these, the Umayyad Mosque, or Great Mosque, is the most important. Said to have been a heathen temple, it was converted into a Christian church at the end of the 4th century. It then contained what was believed to be the head of Saint John the Baptist and was named the Cathedral of Saint John."
"In 635 it was taken by the Muslims, and for a time before the foundation of Baghdad in 762, the city was the residence of the caliphs and was greatly adorned and fortified."
Microsoft® Encarta® Encyclopedia 2002. © 1993-2001 Microsoft Corporation. All rights reserved.
Herod Antipas ll, having beheaded John the Baptist, for criticizing his relationship with Herodias, his Brother Philip's wife, he was next threatened with war by King Aretas, who was indignant at the insult offered to his daughter.
Traditional accounts relate that on this occasion Herod Antipas II sent the head of John the Baptist to King Aretas as a warning of what may happen to those who crossed him.
King Aretas, then sent his Army to fight with Antipas' Army, and defeated him with great loss(Josephus Book 18:Ch.5).
Smiths Bible Dictionary reports: "This defeat, according to the famous passage in Josephus, was attributed by many to the murder of John the Baptist, which had been committed by Antipas shortly before, under the influence of Herodias" (Mat.14:4 ff.; Mar. 6:17 ff.; Luke 3:19"). The head of John the Baptist thus was brought to Damascus where a thriving Christian Church was in existence, and the people all revered John the Baptist as a Prophet.
The head of John was placed in an ornate gilded Sepulcher, in the Church that became known as the "Cathedral of Saint John the Baptist."
This building changed hands several times during the centuries; in 1966 the Umayyad was a Muslim Mosque, and still held the Shrine; allegedly with the Head of John; when I personally visited the Mosque. Certainly my Muslim guide asserted that it was there; but no one questioned the fact that this was indeed the shrine of the head of John the Baptist.
In 37 AD Herod Antipas ll, at the instigation of his wife Herodias, went to Rome to petition for equal kingship with his brother Herod Agrippa. Agrippa outmaneuvered him in the court at Rome; and accused him of high treason.
The case dragged on for two years until in AD 39 Antipas was banished to Lyons in Gaul (France) where he lived and died in great poverty and misery.
When sentence was passed upon him Herodias strenuously opposed the angry Caesar, and as a result she too was stripped of all her personal wealth and her estates, and sent with him into the same banishment.
Josephus, the Jewish historian, sees this as the judgment of God upon her.