Today is Valentines Day (but who is Valentine himself)?

from Garrison Keillor's Writer's Almanac for today (2/14/11):

Today is Valentine's Day.


Everyone agrees that Valentine's Day is named for a Christian martyr named St. Valentine. The problem is, there are at least three St. Valentines, all of them martyrs, and not much is known about any of them. One St. Valentine -- Valentine of Terni, from the second century A.D. -- was a bishop, and he was martyred in Rome, but that's all we know. According to legend, another St. Valentine -- Valentine of Rome -- bravely disobeyed the Roman Emperor Claudius II, who had forbidden young men from getting married because he thought unmarried men made better soldiers. Valentine married people anyway, and he was executed on this day in the year 270 A.D. At some point, it was claimed that both of these saints were martyred on February 14th, but there is no reason to think that it is true in either case.