The significance of these cosmic encounters reaches far beyond aesthetics. Galaxy mergers may, in fact, be some of the most important processes that shape our universe. Colliding galaxies very likely, hold some of the most important clues to our cosmic past and to our destiny. It now seems clear that the Milky Way is continuously undergoing merging events, some small scale, others on a gigantic scale. And the importance of this process in the lives of galaxies is much greater than what was previously thought.