The city of Tyre and its nearby areas are on the Mediterranean coast in modern Lebanon. Tyre was originally an island but became a peninsula when Alexander the Great built a half-mile ramp from the shore in 332 BC.
Tyre had one of the most important harbors on the eastern Mediterranean Sea. People from Tyre had previously come to hear Jesus and see his miracles (3:7–8). This explains how the woman from Tyre knew about him.
There is much discussion about why Jesus left Galilee to visit this Gentile (non-Jewish) region. Mark does not explain the reason, so any suggestion is only a guess.
However, Mark’s Gentile audience would have understood this journey as pointing ahead to the church’s mission to the Gentile world. This mission later led to their own coming to faith (for more about how the church began in Rome, see Romans Book Introduction).