The Xindi incident or Xindi crisis was a series of events lasting nearly a year, from March 2153 to February 2154, involving the Enterprise NX-01's attempt to save Earth from destruction by the Xindi. It was a major turning point in the Temporal Cold War, and the incident also helped pave the way for the creation of the Coalition of Planets, a precursor to the Federation.
In March of 2153, acting on false intelligence provided by the Sphere-Builders, the Xindi launched a surprise attack on Earth. The Xindi, who had been without a homeworld since the 2030s, had been informed by their protectors that, in the 26th century, Humanity was going to destroy their new homeworld.
Because of this, the Xindi-Primate scientist (and Xindi Council member) Degra had been working for several years on a weapon capable of destroying Earth.
Did You Know that Romulan ale was illegal throughout the Federation for at least 100 years before the ban was lifted in 2374, only to be reinstated by 2379, and that despite the embargo, many Starfleetofficers had actually tried the beverage at some time in their career?