But there are three parts to this story. And the first begins over two thousand years ago in Ancient Rome with a single word: et. It’s the Latin for “and”. At some point Roman scribes started combining the two letters of et into a single symbol, which was the ancestor of our modern &. The earliest example of the “et” symbol is actually from graffiti in Pompeii. In any case, it did not disappear with the fall of the Roman Empire. Latin survived as the language of the Catholic Church and of scholarship in Medieval Europe. Scribes during the Dark Ages continued to use the & symbol. It evolved down the centuries, in places losing any semblance of the letters e and t whatsoever.
The second part of the story is that during the 18th and 19th centuries, as education and the teaching of literacy spread, & was added to the end of the alphabet as a sort of 27th letter. On a related note, although “et cetera” is now usually just abbreviated as etc., for a long time it was instead abbreviated as “&c”. The & was for et and the c for cetera.
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