Galba born Servius Sulpicius Galba; 24 December 3 BC – 15 January AD 69) was Roman emperor, ruling from AD 68 to 69. He was the first emperor in the Year of the Four Emperors and assumed the throne following Emperor Nero's suicide.

Born into a wealthy family, Galba held at various times the positions of praetor, consul, and governor to the provinces of Gallia Aquitania, Germania Superior, and Africa during the first half of the first century AD. He retired from his positions during the latter part of Claudius' reign (with the advent of Agrippina the Younger), but Nero later granted him the governorship of Hispania. Taking advantage of the defeat of Vindex's rebellion and Nero's suicide, he became emperor with the support of the Praetorian Guard.  Galba's physical weakness and general apathy led to his being dominated by favorites. Unable to gain popularity with the people or maintain the support of the Praetorian Guard, Galba was murdered on the orders of Otho, who became emperor in his place.

Upon becoming emperor, Galba was faced by the rebellion of Nymphidius Sabinus, who had his own aspirations for the imperial throne. However, Sabinus was killed by the Praetorians before he could take the throne. While Galba was arriving to Rome with the Lusitanian governor Marcus Salvius Otho, his army was attacked by a legion that had been organized by Nero; a number of Galba's troops were killed in the fighting.  Galba, who suffered from chronic gout by the time he came to the throne,  was advised by a corrupt group which included the general Titus Vinius, commander of one of the legions in Hispania; the praetorian prefect Cornelius Laco, and Icelus, a freedman of Galba. Galba seized the property of Roman citizens, disbanded the Germanian legions, and did not pay the Praetorians and the soldiers who fought against Vindex. These actions caused him to become unpopular.

Even before he reached middle life, he persisted in keeping up an old and forgotten custom of his country, which survived only in his own household, of having his freedmen and slaves appear before him twice a day in a body, greeting him in the morning and bidding him farewell at evening, one by one.
His double reputation for cruelty and avarice had gone before him; men said that he had punished the cities of the Spanish and Gallic provinces which had hesitated about taking sides with him by heavier taxes and some even by the razing of their walls, putting to death the governors and imperial deputies along with their wives and children. Further, that he had melted down a golden crown of fifteen pounds weight, which the people of Tarraco had taken from their ancient temple of Jupiter and presented to him, with orders that the three ounces which were found lacking be exacted from them. This reputation was confirmed and even augmented immediately on his arrival in the city. For having compelled some marines whom Nero had made regular soldiers to return to their former position as rowers, upon their refusing and obstinately demanding an eagle and standards, he not only dispersed them by a cavalry charge, but even decimated them. He also disbanded a cohort of Germans, whom the previous Caesars had made their body-guard and had found absolutely faithful in many emergencies, and sent them back to their native country without any rewards, alleging that they were more favourably inclined towards Gnaeus Dolabella, near whose gardens they had their camp. The following tales too were told in mockery of him, whether truly or falsely: that when an unusually elegant dinner was set before him, he groaned aloud; that when his duly appointed steward presented his expense account, he handed him a dish of beans in return for his industry and carefulness; and that when the flute player Canus greatly pleased him, he presented him with five denarii, which he took from his own purse with his own hand.

Accordingly, his coming was not so welcome as it might have been, and this was apparent at the first performance in the theatre; for when the actors of an Atellan farce began the familiar lines "Here comes Onesimus from his farm" all the spectators at once finished the song in chorus and repeated it several times with appropriate gestures, beginning with that verse. Thus his popularity and prestige were greater when he won, than while he ruled the empire, though he gave many proofs of being an excellent prince; but he was by no means so much loved for those qualities as he was hated for his acts of the opposite character.

Particularly bad was his becoming under the influence of Vinius, Laco and Icelus.

On 1 January 69, the day Galba and Vinius took the office of consul,  the fourth and twenty-second legions of Germania Superior refused to swear loyalty to Galba. They toppled his statues, demanding that a new emperor be chosen. On the following day, the soldiers of Germania Inferior also refused to swear their loyalty and proclaimed the governor of the province, Aulus Vitellius, as emperor. Galba tried to ensure his authority as emperor was recognised by adopting the nobleman Lucius Calpurnius Piso Licinianus as his successor. Nevertheless, Galba was killed by the Praetorians on 15 January.  Otho was angry that he had been passed over for adoption, and organized a conspiracy with a small number of Praetorian Guards to murder the aged emperor and elevate himself. The soldiery in the capital, composed not just of Praetorians but of Galba's legion from Hispania and several detachments of men from the Roman fleet, Illyria, Britannia, and Germania, were angered at not having received a donative.  They also resented Galba's purges of their officers and fellow soldiers (this was especially true of the men from the fleet). Many in the Praetorian Guard were shaken by the recent murder of their Prefect Nymphidius Sabinus – some of the waverers were convinced to come over to Otho's side out of fear Galba might yet take revenge on them for their connection to Sabinus.

According to Suetonius, Galba put on a linen corset although remarking it was little protection against so many swords; when a soldier claimed to have killed Otho, Galba snapped "On what authority?" He was lured out to the scene of his assassination in the Forum by a false report of the conspirators. Galba either tried to buy his life with a promise of the withheld bounty or asked that he be beheaded. The only help for him was a centurion in the Praetorian Guard named Sempronius Densus, who was killed trying to defend Galba with a pugio; one hundred and twenty persons later petitioned Otho that they had killed Galba; they would be executed by Vitellius.  A company of Germanic soldiers to whom he had once done a kindness rushed to help him; however they took a wrong turn and arrived too late. He was killed near the Lacus Curtius.  Vinius tried to run away, calling out that Otho had not ordered him killed, but was run through with a spear. Laco was banished to an island where he was later murdered by soldiers of Otho. Icelus was publicly executed.  Piso was also killed; his head along with Galba's and Vinius' were placed on poles and Otho was then acclaimed as emperor. Galba's head was brought by a soldier to Otho's camp where camp boys mocked it on a lance – Galba had angered them previously by remarking his vigor was still unimpeded. Vinius' head was sold to his daughter for 2500 drachmas; Piso's head was given to his wife. Galba's head was bought for 100 gold pieces by a freeman who threw it at Sessorium where his master Patrobius Neronianus had been killed by Galba. The body of Galba was taken up by Priscus Helvidius with the permission of Otho; at night  Galba's steward Argivus took both the head and body to a tomb in Galba's private gardens on the Aurelian Way.