▁Empire . ▁ ▁Don at ários ▁After ▁their ▁discovery , ▁the ▁islands ▁of ▁the ▁Az ores ▁were ▁best owed ▁by ▁the ▁Crown ▁of ▁Portugal ▁to ▁Prince ▁Henry ▁the ▁N avigator , ▁son ▁of ▁King ▁João ▁I , ▁who ▁in ▁turn ▁don ated ▁them ▁to ▁the ▁Order ▁of ▁Christ , ▁of ▁which ▁he ▁was ▁master . ▁The ▁order ▁of ▁succession ▁remained ▁in ▁the ▁hands ▁of ▁the ▁D uk es ▁of ▁V ise u ▁and ▁progress ed ▁as ▁follows : ▁▁ ▁Inf ante ▁Henry , ▁ 1 st ▁Duke ▁of ▁V ise u , ▁( 1 4 3 2 - 1 4 6 0 ) ▁ ▁Inf ante ▁Ferdinand , ▁ 2 nd ▁Duke ▁of ▁V ise u ▁( 1 4 6 0 - 1 4 7 0 ) ▁ ▁Inf ante ▁John , ▁ 3 rd ▁Duke ▁of ▁V ise u ▁( 1 4 7 0 - 1 4 7 2 ) ▁ ▁Inf ante ▁Di ogo , ▁ 4 th ▁Duke ▁of ▁V ise u ▁( 1 4 7 2 - 1 4 8 4 ) ▁ ▁Inf ante ▁Manuel , ▁ 5 th ▁Duke ▁of ▁V ise u ▁( 1 4 8 4 - 1 4 9 5 ) ▁ ▁The ▁D uk es ▁were ▁the ▁direct ▁line ▁to ▁the ▁Crown , ▁pay ing ▁v ass al age ▁as ▁ser fs ▁to ▁the ▁Kings ▁of ▁Portugal . ▁When ▁Manuel , ▁ 5 th ▁Duke ▁of ▁V ise u , ▁asc ended ▁the ▁throne ▁as ▁King ▁Manuel ▁I ▁of ▁Portugal ▁( 1 4