The Birth: Now that the saga of the Green Goblins was over, Marvel felt the need to get another Goblin into the picture. So writer; Roger Stern came up with the Hobgoblin.
A fashion designer who used questionable and ruthless business practices, Roderick developed a financial empire that reached far beyond the fashion industry. Roderick Kingsley was contacted by a petty thief; Georgie, who has stumbled upon the Green Goblin's lair. As all the others who came before him Roderick was lured by all the power that the Green Goblin could offer him. He revamped the suit and the mask and finally put it on for the first time in Amazing Spider-Man #238, although Roderick Kingsley's debut is traced right back to Peter Parker, Spectacular Spider-Man #43.
..... The second Hobgoblin; Ned Leeds, first showed his mug in Amazing Spider-Man #18 but got the Hobgoblin mask out only in Amazing Spider-Man #253 when he was brainwashed by Roderick.

The Alter Egos: Roderick had an identical borther; Daniel who quite often dissapproved of his brothers ways, but covered for him all the same. Many times Daniel use to pass of as Roderick to cover up his brother's whereabouts.
When Roderick wore the mask he proclaimed that unlike his predessesors, he would not let the mask control him. But he was already tethering on a fine line between the sane and the insane.
..... His stand-in, Ned Leeds was better off. He had made a reputation for himself as a good investigative reporter for the Daily Bugle. Much after Peter Parker and Betty Brant were splitsville, he got friendly with Ms. Brant and eventually the two exchanged their marriage vows. Unfortunately, Ned wasn't that successful a husband as he was a reporter and their marriage was constantly on the rocks.

The Legend: When Roderick Kingsley decided that his bank balance needed expanding he put on a mask and became a crazed terrorist. Once he even thought he shot Spidey, but luckily for our hero, it was just his costume that got ventilated.
When he was contacted by Georgie, who had stumbled upon on of Green Goblin's lairs trying to escape from Spider-Man, he had him move all of Gobby's stuff out and then got rid of the thief.
Roderick designed his own outfit and went by the name of the Hobgoblin. His first encounter with Spider-Man was a disaster, proving his inexperience. Thinking that the Green Goblin may have had some special power got him searching for the formula. Finding the liquid, Roderick filtered out what he thought was consuming the insanity side-effects and then consumed the formula, becoming almost as strong as Spidey himself. But insanity was one of the curses of the Goblin mask and he was no exception. This time the mask had chosen someone who was already quite insane.
As the Hobgoblin, Roderick went on a black-mail binge meant to cripple his major competitors. After a fight with Spider-Man left everyone assuming he had drowned, Roderick decided that the direct criminal approach wasn't too healthy for him.
That's when the second Hobgoblin came into play, though right through all the fracas the unsuspecting public thought that there was only one Hobgoblin. When Bugle reporter; Ned Leeds got to close to Roderick Kingsley for comfort, he was kidnapped and then brainwashed by Kingsley. He now used Ned Leeds as a stand-in as the Hobgoblin on many occasions. Under Kingsley's directive, Ned helped Richard Fisk become the Rose and aided Fisk junior during the Gang Wars that almost destroyed New York City.
There was a time when Flash Thompson was framed with evidence of being the Hobgoblin. The cops, the public and even Spider-Man for a time believed it, while the real Hobgoblin was running about freely.
Unlike Kingsley, Ned fought Spidey without any super strength or super agility. Like all the goblins before him, Leeds was primarily a Spidey villain, but his real enemies turned out to be the Jason Macendale who became the next Hobgoblin and the Foreigner. The two worked together to set up Leeds' murder after Kingsley leaked word of Leeds' double life to the underworld. Kingsley had hoped his announcement would get Ned bumped off, since he felt that Ned had become uncontrollable.
Ned Leeds was finally murdered on his from Berlin. After that, another pretender, Jason Macendale became the Hobgoblin. Roderick Kingsley became annoyed with Macendale when Jason brought unwanted publicity with the announcement that Ned Leeds was the original Hobgoblin. The resulting uproar threatened to uncover the unsavoury business practices of Kingsley's coroporation. Returning from Europe, Kingsley murdered Macendale and again assumed the Hobgoblin identity.
All this time, Leeds' widow; Betty Brant had been sleuthing to uncover her husband's muderers. Seems she became fond of Ned just before his death. Her snooping uncovered the trail Kingsley had left behind and with Spider-Man's help, Roderick Kingsley was caught, sentenced and imprisoned for life. Betty managed to clear her husbands name since he had been "brainwashed".

Amazing Spider-Man #238