Yorkie Mitchell served in the Vietnam War in the British SAS. There he met Frank Castle, who saved his life one occasion when Mitchell was injured by enemy fire. After the Vietnam War Yorkie returned to home to Britain and later served in Belfast, Northern Ireland, during "the troubles" and for a long time after when the IRA spent the next couple of decades terrorising Britain. After that, he did work for MI6.
Yorkie Mitchell was created by Garth Ennis and Steve Dillon for The Punisher's Marvel Knights signature series. Later, Ennis brought the character back on several occasions for The Punisher's MAX series, where he proved a durable and quite endearing old hardcase.
First Appearance: Downtown
Frank comes to the United Kingdom looking to find out whose supplying cocaine to the United States. Since he’s new to the area he calls up his friend, Yorkie Mitchell, who informs him that the IRA and their loyalists, who are still fighting the war they’ve been waging for hundreds of years, are those to blame. By now, instead of fighting to kick the British out of Ireland, members of the IRA are fighting the Protestants over territory in the city of Belfast to run narcotics. Yorkie gives The Punisher information on an informant he’s used and Frank goes on his way to kill those trading the drugs.
Major Story Arcs (MAX)
Yorkie Mitchell comes to the United States tracking IRA terrorist Finn Cooley after MI6 determined it was him who blew up an Irish Pub in the Hell's Kitchen district of New York City. The US Government won't authorize a British assassin operating on their home soil but MI6 sends Yorkie regardless. He looks up his old war buddy Frank Castle and they work together to take down Finn Cooley and everyone else involved in the bombing.
Yorkie and Frank track down Finn Cooley and get into a fire fight with him, when matters are made worse by the addition of the River Rats gang to the shootout. Capturing Cooley’s nephew Peter, they discover that Uncle Finn, Maginty, the River Rats and another faction, the Westies, are all searching for a stash of ten million dollars that an old Irish gangster has left behind. It was Cooley that left the bomb in the pub after all, to wipe out the competition.
Dealing with the other gangs including Finn Cooley, as they set up a truce to go find the money and split it, comes to an explosive conclusion...
Deployed to Afghanistan, Yorkie and his team of SAS ops are assigned to safeguard certain endangered members of the Taliban the UK and US wants keeping alive. Unfortunately for them, rogue CIA agent Kathryn O'Brien has taken a personal vendetta out against some of those members for raping her in captivity when her ex left her in Afghanistan for dead. She is captured after being uncovered and Washington wants her disposed of. But before Yorkie is forced to prove his loyalty to the job, Frank Castle calls him up and manages to stop him from doing so by pure luck. Yorkie is later also the man to inform his old friend Frank on where to find her ex, Rawlins, before Frank sets off to murder him in a public restroom.
Long Cold Dark...
...marks the end of Yorkie Mitchell's life as, to get to Frank Castle, the frankly-off-his-rocker mercenary Barracuda breaks into his home, kills his wife in front of him and forces all the information he can get out of him. Before finishing Mitchell off, Frank's war buddy states in all seriousness that he's telling Barracuda where to find Frank because he knows what Frank will do to him. Declaring Castle "the most dangerous man that ever walked this earth," Mitchell reassures Barracuda that he will lose and his words echo in the final moments of Barracuda's life. Not that Yorkie Mitchell was wrong about Castle being the most dangerous man alive, but his final words proved a psychological seed of doubt that helped The Punisher to lay waste to the cheerful psychopath.
In Punisher One-Shot, Get Castle, Frank returns to the UK, this time with the news that Yorkie's son Danny who joined the SAS to be just like his old man, was found hanged on a training exercise in Wales. Frank has been having trouble getting over the death of Yorkie and his wife since Barracuda killed his oldest, most trusted friend of all to get at him. To honour Mitchell's memory and make amends for having not been there when he was needed, Frank quickly sets about establishing his enemies, the SAS boys that murdered Mitchell's son, and bringing their world crashing down and burning. Discovering that Mitchell's son was sold out by a local girl, he doesn't hesitate to cut off the final loose end!