Solely due to my horrible planning mistakes. I'm sure pre-250 is totally achievable.
I missed the moment to mass bulb my scientists by so much that I've discovered the entire tech tree and 7 future techs while building the SS parts, and I missed the Rationalism finisher.
So, soon after I killed Theodora (turn 123) I met the other two AI's on my continent and discovered that in fact I have not the entire continent for my self but only a small part, separated by mountains from the other, larger area.
They both started hating me because Theodora had denounced me before she died, and they likely knew and loved her. I built some frigates in the small closed ocean to the east of Washington (I didn't know it was closed) and attacked GK. Soon it turned out that I only had coastal access to a city of his and two CS's he puppeted. Still, his huge army was good training for my frigates, and liberated city states were of some use. Later I dropped a city to be able to navigate my fleet to the World Ocean. I shouldn't have done this in retrospect (GK war I mean), I thought it would be a start of a great world conquest rampage, but it turned out to be just a huge time sink.
Policy-wise, I closed Patronage before going Rationalism, and that's most likely a huge mistake too. Scholaticism beakers soon became negligible, and Educated Elite was of little use too. I believed I would be able to close Rationalism too, but Nebby couped my two cultural CS's constantly.
Took money from GK for peace, sailed to babylon, upgraded to BS and waited for Nebby to DoW, then killed him outright. Strangely, after his death he still had a spy in Monaco rigging elections in his favor.
Lizzy declared on me along with Nebby, but her ships were nowhere to be found, so I sailed east to her and had enough time to capture three of her cities before the end.
Finally got to feed one CS to another