▁by ▁Manuel ▁Bel gr ano ▁ ▁( which ▁would ▁later ▁become ▁the ▁flag ▁of ▁the ▁Argent ine ▁Republic ), ▁but ▁added ▁a ▁diagonal ▁f esto on ▁in ▁red , ▁red ▁being ▁the ▁sign ▁of ▁federal ism ▁in ▁Argentina ▁at ▁that ▁time . ▁ ▁Original ▁member ▁provinces ▁were ▁the ▁present - day ▁Argent in ian ▁provinces ▁of : ▁ ▁C ór dob a ▁( with ▁La ▁Rio ja ) ▁Cor ri entes ▁Entre ▁R íos ▁M ision es ▁Eastern ▁Province ▁( U ruguay ) ▁Santa ▁Fe . ▁ ▁Down fall ▁ ▁The ▁constant ▁growth ▁of ▁influence ▁and ▁prest ige ▁of ▁the ▁Federal ▁League ▁fright ened ▁Buenos ▁Aires ▁( due ▁to ▁its ▁federal ism ) ▁and ▁Portugal ▁( because ▁of ▁its ▁republic an ism ), ▁and ▁in ▁August , ▁ 1 8 1 6 ▁the ▁latter ▁inv aded ▁the ▁Eastern ▁Province ▁with ▁the ▁intention ▁of ▁destroy ing ▁the ▁prote ctor ▁Art ig as ▁and ▁his ▁revolution . ▁ ▁The ▁Portuguese ▁forces , ▁led ▁by ▁Carlos ▁Freder ico ▁L ec or , ▁thanks ▁to ▁his ▁numerical ▁and ▁material ▁superior ity , ▁conquer ed ▁the ▁Eastern ▁Province ▁and ▁took ▁Monte video ▁on ▁January ▁ 2 0 , ▁ 1 8 1 7 , ▁but ▁the ▁struggle ▁continued ▁for ▁three ▁long ▁years ▁in ▁the ▁coun tr ys ide . ▁Inf uri ated ▁by ▁Buenos ▁Aires ' s ▁pass ivity , ▁Art ig as ▁declared ▁war ▁on ▁the ▁Supreme ▁Director ship ▁at ▁the ▁same ▁time ▁that ▁he ▁faced ▁the ▁Portuguese ▁with ▁arm ies ▁that ▁were ▁being ▁dec im ated