A jocular name for
Tuscany, or at least the
Chianti-growing region within Tuscany, referring to the way so many
English people have
holidays and second homes there.
And not just any English, not the common-as-muck folk who invade the Spanish Costas, but those genteel English of the chattering classes of Islington and Hampstead, of the Shires or Home Counties, who eat radicchio and sun-dried tomatoes and balsamic vinegar, who give it that specially genteel "shire" affix. (Mr Blair seems to go there all the time.)
I thought this was just a journalistic joke, but a Web search throws up many hundreds of hits. Wine companies, villa accommodation, tourism and trekking: it seems to have been accepted by the Italians as a natural English way of naming their region, and they quite unselfconsciously advertise themselves as Chiantishire. They even write it in Italian: Benvenuto nel Chiantishire.