It is impossible to think about any Italian region without wondering ‘What if?’ Sardinia lacks the glamour, grandeur and menace of Sicily, but it is still a fascinating exemplar of Mediterranean culture: the different historical strata stretching back to pre-history. So: what if the mediaeval rulers of Aragon had been more enduring? What if the Catholic kings had never married? There is no reason why Barcelona should have been ruled from Madrid: still less for the Sardinians to be governed by Turin.