True story of Romeo and Juliet?

The people in Verona would like you to believe that the story is true and it all happened between 1301-1304 in Verona, as suggested in the linked website. However useful it is for the Verona tourist industry to have people think the story is true the way it was related by Luigi da Porto, the reality is that da Porto took his story from the earlier story Mariotto and Gianozza by Masuccio Salernitano who published it in 1476 and who claimed that it was a true story that took place during his lifetime . . . in Siena.