 With Agrippina 's influence over her son severed , she reportedly began pushing for Britannicus , Nero 's stepbrother , to become emperor . Nearly fourteen @-@ year @-@ old Britannicus , heir @-@ designate prior to Nero 's adoption , was still legally a minor , but was approaching legal adulthood . According to Tacitus , Agrippina hoped that with her support , Britannicus , being the blood son of Claudius , would be seen as the true heir to the throne by the state over Nero . However , the youth died suddenly and suspiciously on 12 February 55 , the very day before his proclamation as an adult had been set . 
 With Agrippina <a href='null_genetive' title='1'><mark>'s</mark></a>influence over her son severed , she reportedly began pushing for Britannicus , Nero <a href='null_genetive' title='2'><mark>'s</mark></a>stepbrother , to become emperor . Nearly fourteen @-@ year @-@ old Britannicus , heir @-@ designate prior to Nero <a href='null_genetive' title='3'><mark>'s</mark></a>adoption , was still legally a minor , but was approaching legal adulthood . According to Tacitus , Agrippina hoped that with her support , Britannicus , being the blood son of Claudius , would be seen as the true heir to the throne by the state over Nero . However , the youth died suddenly and suspiciously on 12 February 55 , the very day before his proclamation as an adult <a href='been_done' title='4'><mark>had</mark></a> been set . 
With Agrippina  influence over her son severed , she reportedly began pushing for Britannicus , Nero  stepbrother , to become emperor . Nearly fourteen @-@ year @-@ old Britannicus , heir @-@ designate prior to Nero  adoption , was still legally a minor , but was approaching legal adulthood . According to Tacitus , Agrippina hoped that witt her support , Britannicus , being the blood son of Claudius , would be seen as the true heir to the throne by the state ova Nero . However , da youth died suddenly and suspiciously on 12 February 55 , tdavery day b4 his proclamation as an adult done been set .