He is human but he is childhood friends with Lillian Silverstone and has known of magic since his teens. To honor his friend he has taken on the protection of Payton Silverstone and Claire Silverstone.
Keith is born as the first and only child of Mr. and Mrs. Saphire. He grew up in a small house at the edge of Waterfall Creek and always loved playing war with his friends in school. When his father got departed to fight in Vietnam he was left behind with his mother. They lived in constant fear of his father dying there, but when he safely returned things weren't as they used to be. His father suffered from severe panic attacks and nightmares and that scared young Keith, but it also got him thinking.
What could he do to prevent the world from hurting like it did. His grandfather had fought in the second world war and his father was a soldier in the Vietnam war. And there were a lot of ancestors who did something for mankind. He decided he wanted to drop out of school at the age of sixteen and join the army like his father and grandfather and many before them.
He met Jodie Saphire when he was 23 years old and fell in love with her instantly. When she found out she was pregnant, but not with his child he was mad, but his wanted to raise the child like it was one of his own. A couple of months later his first son, Justin Saphire, opened his eyes. A few years later his second son, Chris Saphire, (his real son) was born. Because he was in the military he was away a lot and Jodie had to raise their children on her own. But he always tried to be a father to them. When he was home they made sure they did fun stuff to bond as a family.
When his steph-son comes home with a new girlfriend, Alyssa Miller, he isn't to happy about her. He sees Justin is changing and he'd rather not see the two together. When he gets into a fight with Justin about her things get only worse. Justin moves out and moves in with his new girlfriend. They want him to break up with her, but he refuses. When Keith gets in a car with his wife to go pick up their youngest son Alyssa's father, Jared Carrington, is the cause of a car accident. The car drives of the bridge and both Jodie and Keith can't escape the sinking car, which is the cause of their death.