Given name: Tiberius Claudius Nero

grandson of Marc Antony,
grandson of Livia, 
brother of Claudius &
father of Caligula.

Adopted son & designated heir of Tiberius by order of Augustus.
Popular & successful general. Poisoned by wife of Tiberius' ally, Calpurnius Piso.

References: Josephus, Antiquities 18.54, 164, 206; 19.117, 223, 20.148; 
                  _____, War 2.178.
                  Tacitus, Annals 1-3.
                  Suetonius, Lives of Caesars: Gaius Caligula 1-6.
                  Cassius Dio, Roman History 56-57.

Other resources on line:

• Germanicus Julius Caesar - well-researched biography by Donna Hurley [De Imperatoribus Romanis].

• Germanicus - article in Wikipedia's growing web.

• Bust of Germanicus - image in Barbara Mc Manus' Rome: Republic to Empire (College of New Rochelle).

Bronze coin issued by Claudius in 42 CE presents his dead brother (rather than his uncle Tiberius) as Augustus' original intended heir. The inscription reads: Germanicus Caesar Ti Aug F Divi Aug N ("Germanicus Caesar Tiberius Augustus, son of the divine Augustus"). For high resolution images of this & other coins honoring Germanicus see Joseph Sermarini's excellent numismatic website Forum Ancient Coins.