The use of You for Thou, the plural for the singular, is said to have been introduced in the time of Julius Caesar. Lucan, V , Rowe’s Tr. :⁠—

“Then was the time when sycophants began

To heap all titles on one lordly man.”

“Then was the time when sycophants began To heap all titles on one lordly man.”

Dante uses it by way of compliment to his ancestor; though he says the descendants of the Romans were not so persevering in its use as other Italians. ↩