Spurius Carvilius Rūga was the freedman of Spurius Carvilius Maximus Ruga. He is often credited with inventing the Latin letter G. His invention would have been quickly adopted in the Roman Republic, because the letter C was used for both the and sounds. For example, Ruga's own name contained this ambiguity. In the latter half of the 3rd century BC, Ruga is the first man recorded to have been attested as opening a private elementary school, although other such schools may have existed in Rome prior to his.