Origin

Gralmek was better known as Arne Darvin by Starfleet.  He was born a Klingon but was surgically altered to infiltrate the Federation and poison grain that would kill countless Federation citizens.  He was found out when a tribble gave him away proving his Klingon nationality as tribbles don't like Klingons and give a high pitched squeal when they are around.  
 
Over a hundred years later. Gralmek used a Profit's Tear to go back into time to and Kill James Kirk.  He blamed James Kirk for his discovery as Kirk was the one who used the Tribble to figure out he was a Klingon.  Led by Benjamin Sisko his crew followed Gralmek back in time and caught him.  Bringing him back to his own timeline Sisko managed

Creation

Gralmek was created in the original Star Trek television show although he was only known as Arne Darvin.