Since its first comic book release, the X-Men franchise has grown to include a multitude of characters, many with complex backgrounds that intermingle with those of other X-Men. For those who haven't been following X-Men history religiously, these relationships can seem very complicated. Some mutants are tied by family relation while other have dated, are married to, or are the arch nemesis of other mutants. Some mutants have even been cloned, to make matters more complicated. To answer your questions, here is a complete “family tree” of sorts for the X-Men.