Question: what does the symbol on the portuguese flag mean

title: Flag of Portugal
text: The armillary sphere was an important astronomical and navigational instrument for the Portuguese sailors who ventured into unknown seas during the Age of Discoveries . It was introduced by the Knights Templar , whose knowledge was essential to the Portuguese Discoveries -- Henry , the Navigator , the person mainly responsible for the development of Age of Discovery was actually the Grand Master of the Order of Christ . It thus became the symbol of the most important period of the nation -- the Portuguese discoveries . In light of this , King Manuel I , who ruled during this period , incorporated the armillary sphere into his personal banner . It was simultaneously used as the ensign of ships plying the route between the metropolis and Brazil , thus becoming a colonial symbol and a fulcral element of the flags of the future Brazilian kingdom and empire . 

Answer: answer: The armillary sphere was an important astronomical and navigational instrument for the Portuguese sailors who ventured into unknown seas during the Age of Discoveries.  It thus became the symbol of the most important period of the nation -- the Portuguese discoveries.