- Feb 2022
The idea of the index was invented twice in roughly 1230.
Once by Hugh of Saint-Cher in Paris as a concordance of the Bible. The notes towards creating it still exist in a variety of hands. The project, executed by a group of friars at the Dominican Friary of Saint-Jacques, listed 10,000 words and 129,000 locations.
The second version was invented by Robert Grosseteste in Oxford who used marginal marks to create a "grand table".
The article doesn't mention florilegium, but the head words from them must have been a likely precursor. The article does mention lectures and sermons being key in their invention.
<small><cite class='h-cite via'>ᔥ <span class='p-author h-card'>Aaron Davis</span> in 📑 Monks, a polymath and an invention made by two people at the same time. It’s all in the history of the index | Read Write Collect (<time class='dt-published'>02/15/2022 21:22:10</time>)</cite></small>