Peter I (; ) (died 30 January 969) was emperor (tsar) of Bulgaria from 27 May 927 to 969. His seal reads ΙΠSVΟς·GRECIA·VΟΔΟ. Early reign Peter I was the son of Simeon I of Bulgaria by his second marriage to the sister of George Sursuvul. Peter had been born early in the 10th century, but it appears that his maternal uncle was very influential at the beginning of his reign. In 913 Peter may have visited the imperial palace at Constantinople together with his older brother Michael. For unspecified reasons, Simeon had forced Michael to become a monk and had named Peter as his successor. To prove himself a worthy successor to his father both at home and in the eyes of foreign governments, Peter began his reign with a military offensive into Byzantine Thrace in 927 which was the last campaign of the Byzantine–Bulgarian war of 913–927. Nevertheless, he followed up his quick successes by secretly negotiating a peace treaty before the Byzantine government had a chance to retaliate. The Byzantine Emperor Romanos I Lakapenos eagerly accepted the proposal for peace and arranged for a diplomatic marriage between his granddaughter Maria and the Bulgarian monarch. In October 927 Peter arrived near Constantinople to meet Romanos and signed the peace treaty, marrying Maria on 8 November in the church of the Zoödochos Pege. To signify the new era in Bulgaro-Byzantine relations, the princess was renamed Eirene ("peace"). The extensive Preslav Treasure is thought to represent part of the dowry of the princess. The treaty of 927 actually represents the fruit of Simeon's military successes and diplomatic initiatives, ably continued by his son's government. Peace was obtained with the frontiers restored to those defined in treaties of 897 and 904. The Byzantines recognised the Bulgarian monarch's title of emperor (basileus, tsar) and the autocephalus status of the Bulgarian patriarchate, while the payment of an annual tribute to Bulgaria by the Byzantine Empire was renewed. Revolts and incursions The initial successes of Peter's reign were followed by several minor setbacks. Around 930, Peter faced a revolt led by his younger brother Ivan, who was defeated and sent into exile in Byzantium. Soon afterwards Peter's older brother Michael escaped from his monastery and led a more formidable rebellion, which terminated with his early death. The youngest brother, Benjamin (also called Bojan), was accused of being a werewolf and magician by the Italian Bishop