G is unusual among Latin letters in having a documented birthday. As covered elsewhere in this atlas, early Latin used C for both the /k/ and /g/ sounds inherited from Etruscan, which did not distinguish them. Roman tradition, recorded by later writers such as Plutarch, credits the freedman scribe Spurius Carvilius Ruga with resolving the ambiguity around 230 BCE by adding a short stroke to the base of C, producing a new letter reserved for the voiced /g/ sound. The new G was inserted into the alphabet at the seventh position, the slot Greek zeta had occupied but which Latin, lacking a use for zeta's sound at the time, had left empty since the alphabet's adoption.
Z was later reintroduced at the very end of the alphabet, alongside Y, when Latin needed to spell Greek loanwords, leaving G to hold the seventh spot Z had originally owned. The lowercase g split into two distinct printed shapes during the history of type: a single-story form, close to the capital, common in handwriting and sans-serif fonts, and a double-story form with a closed loop below the line, standard in serif book type since the Renaissance, an unusual case of one letter carrying two unrelated lowercase outlines in ordinary use today.