The Aposltes as proof?

[Trolldor]

One thing I've always wondered, Christians always like to bring up the apostles (or at least their "works" in the bible) as evidence, but has anyone demonsrated that these people existed?

[Beelzebub2]

Not quite - From the Wiki article:

The canonical Gospels are anonymous and were originally untitled, but since at least the second century these documents have been associated with certain personalities, the associations providing the traditional titles: Matthew was to have been written by Matthew, one of the Twelve apostles of Jesus; Mark was to have been written by Mark, an associate of Simon Peter, also one of the Twelve; Luke was to have been written by Luke, a travelling companion of Paul, the Apostle to the Gentiles; John was to have written by John, another of the Twelve.

The first three Gospels, known as the synoptic gospels, share much material. As a result of various scholarly hypotheses attempting to explain this interdependence, the traditional association of the texts with their authors has become the subject of debate. Though some solutions retain the traditional authorship, other solutions reject some or all of these claims. The solution most commonly held in academia today is the two-source hypothesis, which posits that Mark and a hypothetical 2nd source, called the Q document, were used as sources for Matthew and Luke. Other solutions, such as the Augustinian hypothesis and Griesbach hypothesis, posit that Matthew was written first and that Mark was an epitome. Scholars who accept the two-source hypothesis generally date Mark to just prior to 70, with Matthew and Luke dating to 80–90. Scholars who accept Matthean priority usually date all the synoptic gospels to before 70, with some arguing for dates as early as 40. John is most often dated to 90–100, though a date as early as the 60s, and as late as the second century have been argued by a few.

There doesn't seem to be sufficient evidence for existence of any of them since they are mentioned solely in the Gospels written (supposedly) by themselves. How did apostles die?