"Lucius Caesar (Latin: Lucius Julius Caesar; 17 BC – 20 August AD 2) was the grandson of Augustus. The son of Marcus Vipsanius Agrippa and Julia ...
the Elder, Augustus´ only daughter, Lucius was adopted by his grandfather along with his older brother, Gaius Caesar. As the emperor´s adopted sons and joint-heirs to the Roman Empire, Lucius and Gaius had promising political and military careers. However, Lucius died of a sudden illness on 20 August AD 2, in Massilia, Gaul, while traveling to meet the Roman army in Hispania. His brother Gaius also died at a relatively young age on 21 February, AD 4. The untimely loss of both heirs compelled Augustus to redraw the line of succession by adopting Lucius´ younger brother, Agrippa Postumus as well as his stepson, Tiberius on 26 June AD 4." - (en.wikipedia.org 30.01.2020)