Leonard Horatio McCoy is a noted physician and scientist. He is also an accomplished surgeon, xenophysician, exobiologist and an expert in space psychology.

McCoy was born in the "Old South" region of North America in 2227 as son of David McCoy. Leonard was still young when his father became very ill and pleaded with his son to release him from the pain. Seeing his father suffers so painfully McCoy took his father off life support soon before a cure was discovered.

Between 2245 and 2249 McCoy was attending the University of Mississippi where he met the trill Enomy Dax. They might have had some sort of relationship. Dax meant McCoy had the hand of a surgeon and had a feeling he would become a doctor.

Soon after that (2249 - 2253) he joined the medical school.
Leonard never wanted to be anything but a doctor.

From 2267 til 2270 McCoy was joining the USS Enterprise under Captain Kirk. He replaced Dr. Mark Piper. Leonard and Jim became friends and Kirk was the only person who called him "Bones", short for sawbones - the ancient description of a surgeon.

He frequently argued with the first officer Mr. Spock. He thought the Vulcan would be suggestive, cold and intractable.  But nevertheless McCoy respected him and became the "good heart" of the Enterprise and in the friendship Kirk/Spock/McCoy.

His assigned quarters were "3 F 127" on Deck 9, section 2.

In this five years mission he earned the "Legion of Honor" and had been decorated by Starfleet Surgeons.

In 2270 he retired to private medical practise and grew a full beard.

During the 2271 V`Ger Crisis, Admiral Kirk requested McCoy specifically as a member of the Enterprise crew for the investigation of the V`Ger entity. Though both had a big conflict some years ago, Kirk used a "little-known, seldom-used reserve activication clausel" to get his old friend back. He replaced Christine Chapel.

By 2285, Leonard served as an instructor at Starfleet Academy. He joined the Enterprise again who was in fight with Khan, an old Enemy. Within this battle Spock sacrifised hisself. Before he died he nerve-pinched McCoy and performed a mind-meld on the doctor, placing his katra into the doctor`s psyche. The process was traumatic for both, McCoy was going insane. After trying to charter a ship and to reach the Genesis Planet because to re-unite Spock`s body with his katra, Leonard was arrested and was to undergo psychological testing to determine his sanity. But Kirk and Sulu rescued McCoy and with the aid of Scotty, Chekov and Uhura they stole the Enterprise and recovered Spock`s body for return to Vulcan. Spock`s katra was restored via a ceremony. During the mission the Enterprise was destroyed.

The crew stayed on Vulcan for three months and McCoy and Spock fully recovered. Kirk was demoted to a captain and Starfleet gave him command for a new starship, the USS Enterprise-A. McCoy remained as doctor.

In 2293 McCoy and Kirk were arrested and were taken to the penal asteroid Rure Penth. General Chang blamed both for the murder on Klingon chancellor Gorkon. But the charges were fales. The Enterprise found out that Chang plot against Starfleet. Jim and Leonard were rescued and in a last battle the Enterprise destroyed Chang`s Bird of Prey.

The 137-years-old Admiral Leonard McCoy inspected the USS Enterprise-D during its first mission in 2363 and talked with Data.

Leonard was married twice. His first wife named Jocelyn with who he has a daughter named Johanna. But this marriage ended in a bitter divorce and he was seperated from his daughter. In 2268 he married high priestess Natira but they tearfully parted ways.

McCoy doesn`t like transporters and is afraid of dying alone and in pain like his father.