▁his ▁mother . ▁Gem ell us ' ▁young ▁age ▁was ▁another ▁factor ▁in ▁the ▁adv ancement ▁of ▁Cal ig ula , ▁who ▁was ▁made ▁qu a est or ▁in ▁ 3 3 . ▁The ▁two ▁were ▁sum mon ed ▁by ▁T iber ius ▁to ▁Cap ri ▁in ▁ 3 5 ▁where ▁they ▁were ▁made ▁joint - he irs ▁to ▁his ▁est ates . ▁T ac it us ▁records ▁that ▁while ▁they ▁were ▁in ▁Cap ri , ▁T iber ius ▁looked ▁at ▁Cal ig ula ▁in ▁tears , ▁with ▁Gem ell us ▁in ▁his ▁arms , ▁and ▁told ▁him : ▁▁ ▁T iber ius ▁died ▁on ▁ 1 6 ▁March ▁ 3 7 , ▁and ▁Cal ig ula ▁became ▁Emperor . ▁He ▁accomplished ▁this ▁with ▁the ▁aid ▁of ▁Pra et or ian ▁pre fect ▁Mac ro ▁and ▁the ▁cons uls ▁of ▁ 3 7 ▁who ▁agreed ▁to ▁null ify ▁T iber ius ' ▁will , ▁thereby ▁allowing ▁him ▁to ▁inherit ▁all ▁of ▁the ▁est ates ▁which ▁otherwise ▁would ▁have ▁been ▁divided ▁with ▁Gem ell us . ▁Gem ell us ▁was ▁formally ▁granted ▁his ▁to ga ▁vir ilis ▁( t oga ▁of ▁man hood ), ▁was ▁adopted ▁by ▁Cal ig ula , ▁co - opt ed ▁into ▁the ▁Ar val ▁Bre th ren , ▁and ▁given ▁the ▁title ▁of ▁prince ps ▁i u vent ut is ▁( le ader ▁of ▁the ▁youth ). ▁His ▁t iro cin ium , ▁the ▁public ▁ceremony ▁where ▁young ▁men ▁don ned ▁the ▁to ga ▁and ▁became ▁el ig ible