imet ro , ▁an ▁aim ing ▁system ▁that ▁was ▁adopted ▁by ▁the ▁Italian ▁fleet ▁from ▁ 1 9 3 0 ▁on ▁all ▁control ▁shooting . ▁De ▁Fe o ▁collabor ated ▁with ▁the ▁" R iv ista ▁Mar itt ima " ▁from ▁ 1 9 0 6 ▁to ▁ 1 9 3 6 , ▁supporting ▁the ▁strateg ic ▁importance ▁of ▁sub mar ines ▁and ▁aircraft ▁carri ers ▁in ▁naval ▁batt les . ▁As ▁uncle ▁of ▁U go ▁T iber io , ▁he ▁supported ▁his ▁research ▁at ▁the ▁Naval ▁Academy ▁for ▁the ▁development ▁of ▁the ▁Italian ▁rad ar ▁system . ▁ ▁De ▁Fe o ▁was ▁appointed ▁in ▁ 1 9 3 7 ▁Governor ▁of ▁' E rit rea ▁and ▁remained ▁in ▁Italian ▁As m ara ▁since ▁April ▁ 1 , ▁ 1 9 3 7 ▁until ▁December ▁ 1 5 , ▁ 1 9 3 7 . ▁He ▁succeeded ▁to ▁Alfred o ▁Gu zz oni , ▁and ▁was ▁later ▁replaced ▁by ▁Giuseppe ▁Da od ice . ▁ ▁He ▁was ▁appointed ▁Senator ▁in ▁the ▁Parliament ▁of ▁the ▁Kingdom ▁of ▁Italy , ▁on ▁the ▁proposal ▁of ▁the ▁" Min ister o ▁della ▁Marina " ▁on ▁March ▁ 2 5 , ▁ 1 9 3 9 ▁and ▁was ▁sw orn ▁in ▁April ▁ 1 7 , ▁ 1 9 3 9 . ▁ ▁When ▁World ▁War ▁II ▁started ▁De ▁Fe o ▁was ▁assigned ▁to ▁the ▁" Comm ission ▁of ▁Arm ist ice ▁with ▁France ": ▁he ▁signed ▁the ▁Pro tocol , ▁related ▁to ▁the ▁" Ital ian ▁Marina