[RedMonqey]

It’s true, especially if you were fighting your country’s enemies but you still needed the letter of marque to make it legal to do so in defense of your country.

[Svartalfiar]

It’s true, especially if you were fighting your country’s enemies but you still needed the letter of marque to make it legal to do so in defense of your country.

To legally attack ships flying another country's flag, yes. But to defend oneself against attack, or to fight stateless actors (pirates)? No letters of marque were needed.