Admiral Hayes was a Starfleet flag officer from the 24th century. In 2373, when the Borg were detected making their way towards Earth Hayes was in charge of organizing the defense of Earth. During the battle his starship was destroyed, though he would survive its destruction. (Star Trek: First Contact) When the Vendoth arrived in the Alpha Quadrant in 2376, Hayes was placed in charge of the defense of the Sol system. (Star Trek: Unity (crossover): "United We Stand - Together")