The Museum of London Archaeology has deciphered some tablets from AD 40-50 - the first decade of Roman rule.
One of them is a letter from one businessman suggesting another doesn't appear "too shabby" after all the money he's loaned.
The other is some kid's alphabet practice.
And from AD57 they found financial records that have the actual date on. They found a lot. London is basically one big ongoing dig.
(Sorry, had to let my archaeology geek out for once).