aamcnamara

It's quite intelligible, actually. Written Spanish has changed very little in the last several hundred years (although there have been several phonetic shifts in how it's pronounced). It's certainly been much more stable than English, where trying to read the 500-year-old Canterbury Tales is quite trying, and 1000-year-old Beowulf is in an entirely different language, whereas 400-year-old Don Quixote just sounds kind of archaic and the 800-year-old Cantar de Mio Cid is still easier to make out than than the Canterbury Tales, especially if you're also familiar with Portuguese.