How did the New Georgian literary language develop from an East Georgian dialect?

The New Georgian literary language emerged from roots in the secular literature of the 12th century, though its formal conventions were not fully established until the mid-19th century. This development was based on an East Georgian dialect.12

While Old Georgian remained the standard for religious services and theological texts until the early 19th century, the transition toward the modern literary form was supported by a shift toward secular expression and the eventual adoption of more colloquial language in literature. By the 1860s, the rise of prose fiction and the influence of prominent intellectual figures helped solidify this new literary standard, which differs structurally from the older language while remaining largely comprehensible to modern speakers.123