The franc was the currency of Lucca, issued between 1805 and 1808. It was equivalent to the French franc, alongside which it circulated, and was subdivided into 100 centesimi. In 1808, the French franc replaced local coins at par.
See also Luccan lira
Luccan franc Wikipedia
In 1805, silver 1 and 5 franc coins were introduced, followed by copper 3 and 5 centesimi in 1806.