When was the uncial Greek script adapted and abandoned?
Thx for A2A. Being lazy, I refer you to An introduction to Greek and Latin palaeography : Thompson, Edward Maunde, Sir, 1840–1929 : Free Download & Streaming : Internet Archive . From what he says (with nice photos for 1912), the uncial starts in codices 3rd century AD, but is anticipated in papyri in the 2nd century. It survives up until the introduction of lowercase in the 9th century, although by the 8th century it already looks less like Uncial, and more like Cyrillic (which is of course why Cyrillic looks the way it does: it was the Greek handwriting of the time).
Bonus anecdote.
The introduction of lowercase was a disruptive technology much like printing or digitisation or the cloud, and it resulted in the wholesale discarding of earlier, bulkier majuscle manuscripts. There is a cute story relating to the manuscript history of the Vita of St Andrew The Fool (Andrew of Constantinople).
The Vita purports to have been written in the 6th century, but there are enough anachronisms to suspect it was actually written in the 9th. The editor of the text Lennart Ryden found a single leaf of the text, used as padding in the spine of a later manuscript. It was in all capital letters, but they were 9th century capital letters — — which was odd, because by then lowercase had been invented, so noone would be writing in all caps.
Ryden thinks that the leaf was from the original manuscript. The author wanted to pass it off as a 6th century text — — from when people wrote in all caps; but he didn’t realise that the uppercase he was familiar with in the 9th century had changed from what was used in the 6th century. The forgery was so successful, that the original manuscript was copied into normal lowercase — — and thrown out; that’s how a stray leaf ended up as padding.