In Germany and France it was established in the early 1800s. That was when the degree wasn't just a license to teach but you also had to prove you could contribute to research. Oxford was just late to the game. Whether Oxford participated, however, was more irrelevant than not to those other places I'd guess. The US was apparently also late to it, leading to an influx of American PhD students to Germany mid 19th century.
Comments
In Oxford. That hardly counts as universal.
You’re right, maybe roughly circa 1930 across internationally recognized research universities? For some reason I thought Oxford was the holdout.
In Germany and France it was established in the early 1800s. That was when the degree wasn't just a license to teach but you also had to prove you could contribute to research. Oxford was just late to the game. Whether Oxford participated, however, was more irrelevant than not to those other places I'd guess. The US was apparently also late to it, leading to an influx of American PhD students to Germany mid 19th century.