The Bobbio Missal is in the oldest complete Latin Mass Book in Christianity. The parallels seen between its parchment folios and the pages of a Missale Romanum used at a Roman Rite celebrated in the 21st century are too obvious to require underlining. But the word parallel is too general, more often, the Bobbian text is followed word for word. Only when it is placed within its historical chronology, does the connective role played by the Bobbio Missall become clear in the 2000 year course of the Roman Rite. From the Apostolic Age, with its Christian inscription inscribed in graceful Latin letters at Pompeii, some seven centuries were to pass before the time of the copyist at Bobbio, and some seven further centuries were to pass before the Latin Mass was enshrined in the timeless Missale Romanum authorized at the Council of Trent in 1570. Yet, of all the Roman milestones that have come to mark the route of the Latin Mass, none seem to express its validity so fully as the Bobbio Missal.