▁Journal , ▁First ▁Fort y - three ▁S essions ▁of ▁Congress ▁ ▁Bi ographical ▁Directory ▁of ▁the ▁U . S . ▁Congress ▁ ▁U . S . ▁House ▁of ▁Representatives : ▁House ▁History ▁ ▁U . S . ▁Senate : ▁Statistics ▁and ▁List s <0x0A> </s> ▁Geoff rey ▁I , ▁Duke ▁of ▁Brit t any ▁( 9 8 0 ▁– ▁ 2 0 ▁November ▁ 1 0 0 8 ), ▁also ▁known ▁as ▁Geoff rey ▁of ▁R ennes ▁and ▁Geoff rey ▁Ber eng ar , ▁was ▁the ▁el dest ▁son ▁of ▁Duke ▁Con an ▁I ▁of ▁Brit t any . ▁He ▁was ▁Count ▁of ▁R ennes ▁( r uler ▁of ▁the ▁Rom ano - Fran k ish ▁civ itas ▁of ▁R ennes ), ▁by ▁right ▁of ▁succession . ▁In ▁ 9 9 2 ▁he ▁assumed ▁the ▁title ▁of ▁Duke ▁of ▁Brit t any , ▁which ▁had ▁long ▁been ▁an ▁independent ▁state , ▁but ▁he ▁had ▁little ▁control ▁over ▁much ▁of ▁Lower ▁Brit t any . ▁ ▁Life ▁Geoff rey ▁was ▁the ▁son ▁of ▁Duke ▁Con an ▁I , ▁by ▁his ▁marriage ▁to ▁Er m eng arde - G er berga ▁of ▁An jou . ▁He ▁was ▁the ▁grand son ▁of ▁Jud ica el ▁Ber eng ar , ▁Count ▁of ▁R ennes . ▁ ▁When ▁Geoff rey ▁succeeded ▁to ▁Brit t any ▁he ▁had ▁several ▁problems : ▁Blo is ▁was ▁enc ro aching ▁on ▁his ▁territory , ▁Vik ings ▁were ▁threaten ing ▁his ▁sh ores , ▁and ▁he ▁had ▁to ▁decide ▁whether ▁to ▁accept