PRE TEMPORAL FLUX
The 19th Fleet was founded in 2293 by Admiral Nogura because the Federation was on the verge of war with the Klingons. It was disbanded in 2295 and later refounded during the Dominion Wars. It has been redisbanded after the war ended, but was refounded yet again on stardate 87742.07 when Admiral Necheyev decided the Fleet could be used in the border skirmishes against the Klingon Empire. And then in 2414 the Fleet entered Sector 14, along with the 23rd Feet, and consequently all were thrown into a temporal flux.
POST TEMPORAL FLUX
Most of the 19th and all of the 23rd Fleet got unstuck in time because of this flux, because not everyone had a flux capacitor installed, since the capacitor was only an experiment in its early stages it had not yet rolled out to the rest of the 19th Fleet, let alone the rest of Starfleet. And thus the few that had a flux capacitor start anew from scratch in 2944. After arriving in 2934 they kept cruising the galaxy for 6 years until they met the scouts of FROG this encounter soon evolved into a very close alliance which still stands today.