The flag, formally adopted as Marineflagge was based on the colours of the Archduchy of Austria. It served as the official flag also after the Ausgleich in 1867, when the Austrian navy became the Austro-Hungarian Navy. During World War I, Emperor Franz Joseph approved of a new design, which also contained the Hungarian arms. This flag, officially instituted in 1915, was however little used, and ships continued displaying the old Ensign until the end of the war.
The Portuguese Navy (Marinha Portuguesa, also known as Marinha de Guerra Portuguesa or as Armada Portuguesa) is the naval branch of the Portuguese Armed Forces. The Portuguese Navy also participates in missions related with international compromises assumed by Portugal (mainly with NATO), as well as missions of civil interest. The Portuguese Navy, tracing back to the 12th century, is the oldest continuously serving navy in the world.