Hello again ttif,
If you want something less crowded but still with a medieval theme you could go to Medievo in Val di Lima on evening of July 26th in the hill village of Casoli which is one of the Bagni di Lucca villages. We went last year, lovely evening. As with many of the medieval festa evenings you pay an entry fee to the village and are given a map, you follow the route eating and drinking traditional local foods along the way. There are various medieval themed entertainments and plenty of people dressed in costume. There are lots of these sort of events around Bagni di Lucca through the summer, though this one fits with your dates. Check with the tourist information office at the former Royal Casino in Ponte a Serraglio, the lady who runs it is very helpful and can tell you what's on. Also pick up the leaflet 'Bagni d'Estate' which list summer events. Often though posters and publicity here only appear literally days before an event! Keep your eyes open! There is also the Palio di San Jacopo at Gallicano, which is about 15mins north of Bagni di Lucca, July 25th flag throwing and floats, evening I think.
Caroline, Villa Rosalena.