The Federation Civil War
At some point prior to the beginning of the series, an event known as the Restoration of Vulcan, which had been kept hidden since 2523, had been revealed to the public under unknown circumstances.
The Civil War was sparked when a number of planets seceded from the Federation, calling themselves the Terra Federation, they place the rights of human beings over those of other species. In addition, a Second Restoration of Vulcan occurred taking advantage of the chaos of the Civil War, the Vulcans broke off from the Federation creating the Vulcan Imperium.
Now, its been 5 years since the end of the Civil War, and the Federation is picking up the pieces. Calling on its allies, they have managed to construct the new Galileo-class ships, and at the head is the USS Enterprise-K.
With the end of the Civil War, the Federation is struggling to return to their goals of exploration. Barely holding together the planets that are left, they are fighting to reunite the planets that seceded from the Federation.
The Enterprise will not be limited to this effort, traveling across the great distances, the crew will travel to the farthest reaches of the Universe to complete the mission set down so long ago.