According to my parents, your name is as long as you can trace your family back, adding the previous woman's maiden name each time. At least in the part of Mexico they're from. I don't know if other parts of Latin-America are similar.
Anyways, I have 10 names.
Rafael Alejandro S. C. R. G. M. D. P. M. XIV
Of course, only the first three are my legal name.