21 or 22 March, in a mutiny of the Legio XXII Primigenia at Moguntiacum (Mainz) while at a meeting with his generals. These assassinations secured the throne for Maximinus. The Historia Augusta documents two theories that elaborate on Severus's assassination. The first claims that the disaffection of Mamaea was the main motive behind the homicide. However, Lampridius makes it clear that he is more supportive of an alternative theory, that Alexander was murdered in Sicilia (located in Britain). This theory has it that, in an open tent after his lunch, Alexander was consulting with his insubordinate troops, who compared him to his cousin Elagabalus, the divisive and unpopular Emperor whose own assassination paved the way for Alexander's reign. A German servant entered the tent and initiated the call for Alexander's assassination, at which point many of the troops joined in the attack. Alexander's attendants fought against the other troops but could not hold off the combined might of those seeking the Emperor's assassination. Within minutes, Alexander was dead. His mother, Julia Mamaea, was in the same tent with Alexander and soon fell victim to the same group of assassins. Alexander's body was buried together with the body of his mother, Julia Mamaea, in a mausoleum in Rome. The actual mausoleum, called , is the third largest in Rome after those of Hadrian and Augustus. It is still visible in Piazza dei Tribuni, in the Quadraro area in Rome, where it resembles a large earth mound. The large sarcophagus found inside the tomb in the 16th century, and which contained the emperor's remains, is in the Palazzo dei Conservatori Museum in Rome. According to some sources inside the same sarcophagus in 1582 a precious glass urn was found, the Portland Vase, currently on display at the British Museum in London. Legacy Alexander's death marked the end of the Severan dynasty. He was the last of the Syrian emperors and the first emperor to be overthrown by military discontent on a wide scale. After his death his economic policies were completely discarded, and the Roman currency was devalued; this signaled the beginning of the chaotic period known as the Crisis of the Third Century, which brought the empire to the brink of collapse. Alexander's death at the hands of his troops can also be seen as the heralding of a new role for Roman emperors. Though they were not yet expected to