John spent most of his life living in a mountainous area of Judah that was between Jerusalem and the Dead Sea. His diet was strict and he dressed rather roughly (like Elijah - Matthew 3:4, Mark 1:6, 2Kings 1:8). His ministry began when he was 30 in 26 A.D. It lasted for about three years until put in prison by Herod Antipas for speaking out against his unlawful marriage. Because of a promise Herod made to his wife's daughter Salome, he had the Baptist beheaded just before the Passover in the Spring of 29 A.D.
John the Baptist had an effective and popular ministry which drew the attention not only of the average person but also of Priests, Pharisees, Sadducees, Herod Antipas (Roman ruler of Galilee and Perea) and others (John 1:19, 24; Matthew 3:7, Mark 6:16 - 19, etc.). He also drew his share of disciples. The first two people Jesus called to follow him were first followers of him (Jn. 1:35 - 39).
John's students were so zealous for him that when they saw Jesus baptizing more people they told him about it - as if something was wrong. He assured those who followed him that 'He must increase, but I must decrease.' (Jn. 3:26 - 30, NKJV throughout). In time they eventually approached Jesus with a question that had puzzled them "'Why do we and the Pharisees fast often, but Your disciples do not fast?' " (Matthew 9:14). Jesus responded using a wedding analogy to explain the difference (verse 15).
After Herod tossed John into prison, he had plenty of time to think. Although he had proclaimed Jesus as the lamb of God, he had not personally witnessed his miracles. He began to hear about the works of Christ. He may have wondered why Jesus did not miraculously deliver him from prison. Therefore, he sent two of his disciples to ask Jesus 'Are You the Coming One, or do we look for another?' (Matthew 11:3). Jesus told those sent to him to report back what they heard and saw - the blind see, the lame walk, the deaf hear, etc. (verse 4 - 5).
Jesus' own disciples, struck with the zealousness of 'the voice in the wilderness' and his teaching methods, asked Jesus "Lord, teach us to pray, as John also taught . . . " (Luke 11:1). The prayer format they received is the 'Lord's Prayer' (verse 2 - 4).
John had a tremendous impact on those in Jerusalem and Judea even after his death. In fact, when Herod (who beheaded him) heard about Jesus he said 'John the Baptist is risen from the dead, and therefore these powers are at work in him.' (Mark 6:14, NKJV). The memory of his zeal and the lasting effect of his work continued both in his disciples and in the early church. There were those, like Apollos, who did not know who Jesus was but who spread the gospel based on what 'the baptizer' taught them (Acts 18:24 - 28). In Ephesus, the apostle Paul ran across some believers who were taught and baptized by him but who knew nothing about receiving God's spirit that would enable them to be converted (Acts 19:1 - 6). He was truly the greatest of all the Old Testament prophets.