The 12 apostles, also known as the 12 disciples, left their mark on Christianity as the closest followers of Jesus Christ. Although one of the original apostles, Judas Iscariot, famously hanged himself after betraying Jesus, Christian texts purport that the other apostles continued to spread the gospel after Christ's crucifixion, although they perhaps lacked the unity and strength they possessed during his life.

Andrew

According to the text of the theologian Hippolytus of Rome, Andrew, like most of the apostles, died a martyr. This text tells of Andrew's hanging on an olive tree in Patrae, Achaia, about the year 70. Before his death, Andrew is said to have preached the gospel of Christ to the Thracians and Scythians. Other traditions tell of his crucifixion in a spread-eagle position, according to texts compiled by the Christian Classics Ethereal Library.

Bartholomew

Like Andrew, Bartholomew -- also known as Nathanael -- is believed to have met his end by martyrdom about 70 A.D., after years of missionary work in Armenia and India. Little is written of Bartholomew's death, but Christians believe him to have stayed faithful until the end, when he was crucified.

James, Son of Alphaeus

The apostle James, son of Alphaeus, fell to the sword of Herod Agrippa about 45 A.D., according to Acts 12:2. The historian Eusebius' "Church History" states that James' executioner was so inspired by the apostle's unwavering faith that he proclaimed his belief in the resurrection of Christ and was executed alongside James.

James, Son of Zebedee

James, Son of Zebedee, led the Christian church in Jerusalem after the death of Christ. In 63 A.D., Christian scholars believe James met his end at the hands of three men who asked him to refute the validity of Christ's resurrection. When he refused, he was thrown from the top of his temple.

John

Although John was the only apostle who was not martyred, he was exiled to the Island of Patmos by the Roman Emperor Domitian, or perhaps Nero, for his faith. Traditions say John wrote the Bible's Book of Revelation before dying of natural causes between the years 95 and 100.

Matthew

In the years after Christ's death and resurrection, Matthew the tax collector is best remembered for penning the Gospel According to Matthew. About 10 years later, between 60 and 70 A.D., Christians believe Matthew was martyred by beheading in Nad-Davar, Ethiopia. Although it is a point of contention, some scholars attribute the first Gospel of the New Testament to Matthew.

Paul

Although Galatians 1:13 illustrates Paul as a nonbeliever, he was converted by the resurrection of Christ. Commonly regarded as the disciple who replaced Judas Iscariot, Paul -- who is credited for more than half the books of the New Testament -- eventually earned his place as one of the most significant apostles. Throughout his life, Paul suffered beatings as his ministry preached Christianity until the Roman Emperor Nero beheaded him around 67 A.D.

Peter

Days after his crucifixion, Christ appeared to Peter, according to the gospels. In this moment, Peter seems to transition from a hot-tempered disciple to a leader who -- in the Acts of the Apostles -- performs miracles and preaches passionately. Non-Biblical texts and traditions typically state that he was crucified in Rome on an upside-down cross between 64 and 67 A.D. The first Christian emperor of Rome, Constantine, believed Peter to be buried near the Vatican Hill, and bones found in a 1939 archaeological dig may support this belief.

Philip

After the resurrection of Christ, Philip is thought to have spread the gospel through Phrygia, or modern-day Turkey. Philip served as a dedicated apostle until about 54 A.D., when he was tortured and crucified by Phrygian Jews.

Simon

Christian historians believe Simon to be among the most well-traveled of the apostles, spreading the word through territories as diverse as Egypt, Libya and Persia until meeting his death at the hands of a Syrian governor in 74 A.D. Like his fellows, Simon is thought to have died a martyr.

Thaddaeus

Christian scholars such as Michael Patton of Credo House Ministries believe Judas Thaddaeus, or Jude, continued to evangelize after the death of Christ. Patton writes that pagan priests in Mesopotamia beat Thaddaeus to death with sticks about 72 A.D., making him another apostle who died a martyr.

Thomas

In John 20:25, Thomas initially doubted the resurrection of Christ. After Christ appeared to Thomas himself, the apostle continued to preach the gospel and reportedly wrote the Acts of Thomas and the non-canonical Gospel of Thomas. It is believed that he was also martyred around 70 AD; some stories tell of death by extreme torment, including spears and hot plates.