Most interesting are the Macchiaioli (from the verb macchiare, to blotch or stain) school of Tuscan pre-Impressionists, who met at Florence's Cafe Michelangelo in the 1860s seeking a new freedom from academic art that paralleled the political liberation of the Risorgimento.
They only met once in the first year of meeting, but then went on to meet every 4 weeks 5 years later.