From being drunk on the job to deliberate foul play to simple yet horrific mistakes - this list proves that execution doesn't always guarantee a quick death:

Mary Queen of Scots

Traditionally royalty got a bit of a break when it came to execution. If condemned to die, they were usually ordered to be beheaded, and by an experienced executioner who was skilled enough to do the job with one blow to the neck. Unfortunately, for Mary Queen of Scots she did not receive quite the royal treatment.

She was beheaded for treason on February 8, 1587 and on the first blow it missed and hit the back of her head. She supposedly groaned in pain, and was killed by a second blow. Her head still attached, it took a final third strike to decapitate. The executioner then lifted the head and said "God Save the Queen" only for it be revealed that Mary had been wearing a wig and her head dropped and rolled onto the ground in front of several hundred shocked witnesses.

Thomas Cromwell

Thomas Cromwell was a loyal servant with Henry VIII, until Henry feared he was gaining too much control and fell out of his good books. He was arrested in 1540 with multiple charges that he had acted against the King, including high treason. He was not granted a trial but was spared being hung, drawn and quartered and sentenced to be beheaded.

He was beheaded on 28 July 1540 aged between 54 and 55. It was rumoured at the time that he was given a poorly skilled executioner and that it took several blows to decapitate him. His contemporary, chronicler Edward Hall wrote that Cromwell, "So paciently suffered the stroke of the axe, by a ragged and Boocherly miser, whiche very ungoodly perfourmed the office.

Margaret Pole, Countess of Salisbury

Margaret Pole was the daughter of George, Duke of Clarence, the Brother of Richard III and Edward IV. She was executed by the son of her cousin - Henry VIII - on 27 May 1541. She was aged 67.

Sentenced to be beheaded for supporting Roman Catholicism and conspiring against the King, her execution was far from dignified. She refused to accept that she was guilty and had to have her neck forcibly placed on the execution wooden block. The executioner was inexperienced and hacked multiple times to her neck, head and back. It reportedly took eleven blows until she was declared dead.

Jim Robinson

In 1852 Jim Robinson, "Yankee Jims" was hung in California, USA. Although no hard evidence was found against him he was sentenced to be hung for thievery in front of a crowd of several hundred in what is now modern day San Diego. Trouble is, it was one of the first hangings in the newly pioneered lands and the hang man was inexperienced.

The scaffolding wasn't high enough for Jim Robinson's supposed tall frame and his feet touched the ground as he was hung. It took a reported 40 minutes for him to gradually strangle to death.

Louison Cartouche

Louis Dominique Garthausen was French Robin Hood like highwayman and vagabond. he was arrested and publicly executed by being broken on the wheel in 1721. While being placed on the wheel (a torture/execution device in the shape of the wheel in which all of your bones are broken as you are gradually spun) was not a great way to go, the fate for his younger brother Louison was even crueler.

Aged just 15, Louison was sentenced to a non lethal hanging as more of a warning to not follow in the same steps of his brother than an intended execution. He was hung upside by his armpits and left for crowds to taunt him. However, after just two hours his tongue rolled out and he was declared dead.

William Kemmler

William Kemmler was the first known person in the world to be executed by the electric chair. He was convicted of murdering his common-law wife with a hatchet and was executed via the electric chair on August 6, 1890.

However, all did not go to plan. Before the electric currents were switched on, Kemmler apparently said, "Take it easy and do it properly, I'm in no hurry." The current passed through his body for 17 seconds at the power of 1,000 volts. This was believed to be strong enough to kill a grown man.

Although he was declared dead, witnesses said they could still see him breathing. A second wave of currents were applied to Kemmler, this time at 2,000 volts. Witnesses spoke afterwards that parts of his flesh burst and even set on fire. The execution took a total of eight minutes and was exposed by the press at the time, with one newspaper remarking an axe would have been a more humane method.

Wallace Wilkerson

Wallace Wilkerson was an American stockman who was accused of fatally shooting a man following a dispute over a card game of cribbage. He was sentenced to be executed on May 16, 1879 by a firing squad.

Witnesses claim Wilkerson appeared to be drunk on the day of his execution, and he declined to be blindfolded when preparing to be fatally shot by the squad. The squad missed his target of the heart, and instead hit him in the arm and torso multiple times. Wilkerson leapt from his chair after the shots and yelled, "Oh, my God, my God! They've missed it!" Doctors rushed to him and questioned whether they should shoot him again. He was pronounced dead 27 minutes later, having bled to death.

Jimmy Lee Gray

Jimmy Lee Gray was executed on September 2, 1983 for kidnapping, raping and murdering a three year old girl. Executed by lethal gas, it wasn't administered properly and it took him over ten minutes to die. Declared dead by falling and hitting his head, the press reported hearing "eleven moans" and that witnesses were cleared after eight minutes because the scene was so distressing.

It later emerged that the executioner had not administered enough gas to cause a quick death (it is meant to take only around two minutes to die by lethal gas) because he was drunk.