Trouble is, there was no San Marino at the time. While I have no idea whether or not this was the inspiration for Tolkien, some element sort of match, from the

Trouble is, there was no San Marino at the time. While I have no idea whether or not this was the inspiration for Tolkien, some element sort of match, from the capital being moved to the following reconquest of Ravenna under Byzantine rule, and also the presence of marshes to the north of the city (if Middle Earth map is oriented North-top South-bottom, which I'm not sure).