Some speculative sources say that Dante had…
November 1310 CE
Some speculative sources say that Dante had also been in Paris between 1308 and 1310.
Other sources, even less trustworthy, take him to Oxford.
When Henry VII of Germany marches five thousand troops into Italy in November 1310, Dante, seeing in Henry a new Charlemagne who will restore the office of the Holy Roman Emperor to its former glory and also retake Florence from the Black Guelphs, writes to the King and several Italian princes, demanding that they destroy the Black Guelphs.
Mixing religion and private concerns, he invokes the worst anger of God against his city, suggesting several particular targets that coincide with his personal enemies.
It is during this time that he writes the first two books of the Divine Comedy.