(Continued)
A thing to keep in mind is that German scholarship and British scholarship are different worlds entirely. While in Germany, you may have things like the shift in theories or Bismarck going on, the same was not necessarily the case in England.
(This scholarship divided along national lines still holds true to an extent today; even today you have an American side of academia, a German side, a UK side, etc. It’s not always the case that a scholar from a certain side can make a name for themselves into another side: some scholars are so influential that they’re internationally-recognized to the point that even a layman knows them, while others are only really well-known within their respective countries. I mean, while I think you’ve heard of Robert Funk (from the US side) or NT Wright (UK) or Martin Hengel (Germany), can you say the same thing about say, Kenzo Tagawa (Japan) or Fr. Erich Zenger (Germany)?)
In England, Markan priority arrived first before ‘true’ two-source hypothesis. Before that happened, many English scholars had a different solution to the synoptic problem than their German counterparts: they argued for a non-literary, oral origin to the gospels. In other words, no one copied from another; any similarities between the three gospels must have been due to them using the same oral tradition independently. (This was Westcott’s - of the Westcott and Hort NT fame - theory.)
But then came William Sanday (1843-1920), who imported Holtzmann’s theory to England around the 1870s. It is in England that the two-source hypothesis became closer to the form of the theory we know today.
Holtzmann’s theory was
not ‘true’ Markan priority: he thought that Matthew and Luke used, not so much Mark’s gospel, but a proto-gospel that strongly resembled Mark’s:
Ur-Markus. Mark’s gospel, in Holtzmann’s theory, was an independent adaptation of this ‘proto-Mark’. English scholars at Oxford studied Holtzmann’s theory and felt that he was unnecesarily multiplying sources: rather than postulate the existence of a ‘proto-Mark’, why couldn’t have Matthew and Luke simply used Mark outright? In fact, from then on it was mostly British scholars who modified Holtzmann into the form we know the theory today: J. C. Hawkins (1899), F.C. Burkitt (1909), B.H. Streeter (1924). This modified form of Holtzmann became the standard, eventually even in its native Germany.
(Funnily enough, it was an Oxford professor who was one of the first in the English-speaking world to receive Holtzmann’s theory (William Sanday), an Oxford professor who modified the two-source hypothesis into its current form (B.H. Streeter), and an Oxford professor who was one the first to ditch Q (Austin Farrer). You might say that Oxford just completed the process: first they got rid of Ur-Markus, then it was Q’s turn.

)