Era beginning/end
The Treaty of Coruscant was signed at the end of the 1st Great Galactic War. Modern scholars accept it as the endpoint of the Old Republic Era.
While some have argued that the galaxy experienced its true shift at the start of the great galactic war, Master Gnost-Dural argued that it was only with the signing of the treaty that the galactic community in general, and the Republic in particular, truly accepted that the Republic was no longer an unbreakable, undefeatable political entity.