What day is Portugal independence?

Answer 1

There's none. And it would be pointless and child's play, either by society itself, historians or politicians to choose one, for the following reasons: Portugal, was mostly a creation of the 12th century. In the 12th century there was no such "Declaration of Independence" in modern terms, but a series of consecutive events that would eventually led to political Independence. So like many other medieval born countries, one could celebrate today several episodes that in our modern perspective were part of that creation: a specific battle, a treaty, a special visit from the Pope, a recognition of one dinasty as the primary between pairs in or out of the battlefield, and so on. So choosing a particular event would always be anachronic, since all events combined are the real statement of Independence. And that is what happened to Portugal in the 12th century: one can link many events, like the Battle of Sao Mamede, in 1128, where the future king takes control of the county. The Battle of Ourique, in 1139, where is considered king by his pairs. The so called "Treaty" of Zamora in 1143, where there was a reconfiguration of powers. And the Pope's recognition in 1179.

Also the country should rightly celebrate many other events, like the reconquest of the independence in 1640 (otherwise it wouldn't be an independent country today) - a national holiday, because in 1640 we can call one specific day a clear modern statement of interests.