Nightwatch was Doctor Kevin Trench, who witnessed a costumed man die battling some terrorists armed with invisibility-generating 'cloaking" devices, and unmasked the corpse to learn that it was an older version of himself. His first appearance was in Web of Spider-Man #099.
Freaking out, Trench stripped the costume from "his" body and fled to a deserted island, reasoning that if he just never wore the suit or went home, he wouldn't die (Web of Spider-Man #100). Events conspired to bring him back, as the criminal Alberto stole one of the costume gloves after washing up on the island and being nursed to health by Trench (Web of Spider-Man #98-9). After Alfredo had been dealt with, Trench decided that he couldn't avoid his destiny, and decided to investigate the costume's origins.
In the interim, he battled menaces like the "Maximum Carnage" gang and the mutated Deathmask, Graduating into his own book, Nightwatch encountered similar "cloaked" villains, and was shocked when their technology merged with and enhanced his costume. In between battling menaces like Flashpoint, Cardiac (whose technology had been stolen to create the more vicious Cardiaxe), and Venom, Nightwatch discovered that an old ex-girlfriend was working for the shady Morelle Pharmaceuticals on a nanotech project.
Ultimately, project head Phillip Morelle proved to be corrupt, and Nightwatch defeated his sinister plans. Justin Morelle, the son of Phillip and Trench's ex, received nanotech arms from the project in the bargain. Nightwatch's costume boosted his strength and durability by triggering his adrenal glands, and nanotechnologically repaired itself.
Its cape responded to his subconscious thoughts to move on its own, and allowed him to glide on air. After he was boosted by the later-generation Morelle technology, the durability of the costume increased, the cape became more metallic, and he had something closer to true flight.
Nightwatch was an innocent victim of the Great Game. While trying to protect Justin, he was slain by the mercenaries Polestar and El Toro Negro. Polestar used the magnetic powers of his costume to peel away just enough of Trench's nanite costume for El Toro Negro to shoot him point blank in the chest. El Toro Negro then immediately turned on Polestar, shooting him between the eyes.