The narratives about the birth and childhood of the Baptist in Lk 1-2 EU are probably of little historical weight. Here some theologians assume personal legends from the circle of the Baptist worshippers, who want to transfer the later meaning of the Baptist already to the events around the birth and childhood of John and illustrate them with the help of Old Testament motifs. But these texts are by no means unproductive for a historical reconstruction. According to Lk 1,13-15 EU John is announced before his birth by the angel Gabriel as a man abstinent from wine and intoxicating substances. According to Am 2,11f EU this wine asceticism can be interpreted as characteristic for prophets.
John probably comes from a priestly lineage: According to Luke's gospel John was the son of the priest Zacharias from the priestly class Abijah and Elizabeth from the lineage of Aaron (Lk 1,5 EU). Since the priestly class Abijah was one of the less important of the 24 priestly classes (1 Chr 24,19 EU), this could well be a reliable information.
According to Lk 1,5 EU John was born "in the time of Herod, king of Judea"; he reigned from 38 B.C. to 4 B.C. In Lk 1,39 EU the reader learns about the place of residence of Elizabeth: "a city in the mountains of Judea". Already this imprecise information indicates the low historical interest of the author, who is essentially interested in a statement on the theological level of meaning.
Speculations about a Qumran stay of the young John based on Lk 1:80 EU cannot be historically verified. With the specification "lived in the desert until the day when he received the commission to appear in Israel" the motive of staying and working in the desert, which characterizes the Baptist as a prophet, might have been brought forward to the time before his calling.