Gutenberg in a 16th-century copper engraving
Gutenberg was born in the German city of Mainz, the youngest son of the patrician merchant Friele Gensfleisch zur Laden, and his second wife, Else Wyrich, who was the daughter of a shopkeeper. It is assumed that he was baptized in the area close to his birthplace of St. Christoph. According to some accounts, Friele was a goldsmith for the bishop at Mainz, but most likely, he was involved in the cloth trade. Gutenberg's year of birth is not precisely known, but it was sometime between the years of 1394 and 1404. In the 1890s the city of Mainz declared his official and symbolic date of birth to be June 24, 1400.
John Lienhard, technology historian, says "Most of Gutenberg's early life is a mystery. His father worked with the ecclesiastic mint. Gutenberg grew up knowing the trade of goldsmithing." This is supported by historian Heinrich Wallau, who adds, "In the 14th and 15th centuries his [ancestors] claimed a hereditary position as ... retainers of the household of the master of the archiepiscopal mint. In this capacity they doubtless acquired considerable knowledge and technical skill in metal working. They supplied the mint with the metal to be coined, changed the various species of coins, and had a seat at the assizes in forgery cases."
Wallau adds, "His surname was derived from the house inhabited by his father and his paternal ancestors 'zu Laden, zu Gutenberg'. The house of Gänsfleisch was one of the patrician families of the town, tracing its lineage back to the thirteenth century." Patricians (the wealthy and political elite) in Mainz were often named after houses they owned. Around 1427, the name zu Gutenberg, after the family house in Mainz, is documented to have been used for the first time.
In 1411, there was an uprising in Mainz against the patricians, and more than a hundred families were forced to leave. As a result, the Gutenbergs are thought to have moved to Eltville am Rhein (Alta Villa), where his mother had an inherited estate. According to historian Heinrich Wallau, "All that is known of his youth is that he was not in Mainz in 1430. It is presumed that he migrated for political reasons to Strasbourg, where the family probably had connections." He is assumed to have studied at the University of Erfurt, where there is a record of the enrolment of a student called Johannes de Altavilla in 1418—Altavilla is the Latin form of Eltville am Rhein.
Nothing is now known of Gutenberg's life for the next fifteen years, but in March 1434, a letter by him indicates that he was living in Strasbourg, where he had some relatives on his mother's side. He also appears to have been a goldsmith member enrolled in the Strasbourg militia. In 1437, there is evidence that he was instructing a wealthy tradesman on polishing gems, but where he had acquired this knowledge is unknown. In 1436/37 his name also comes up in court in connection with a broken promise of marriage to a woman from Strasbourg, Ennelin. Whether the marriage actually took place is not recorded. Following his father's death in 1419, he is mentioned in the inheritance proceedings.