For the first time of its kind in the world, the authorities in the US state of Alabama used nitrogen gas to carry out an execution on a prisoner, sparking widespread controversy worldwide.

According to the British "BBC" network, it was initially planned to execute prisoner Kenneth Eugene Smith - accused in the murder case of a preacher’s wife in 1988 - by lethal injection in November 2022, but after its failure, the state used nitrogen gas to execute him, by placing a mask centered on his face.

Although about half of the US states still apply death penalty laws by different methods, such as states that still allow execution by hanging, shooting, or using the electric chair, Smith’s execution by nitrogen gas became the most controversial method in the world after its implementation in Alabama.

But, what are the strangest methods of executing the death penalty known to humanity?

The death penalty is considered one of the most controversial and criticized punishments, and over the ages, humanity has witnessed developments in its execution methods, having invented strange and horrific ways to achieve justice, according to the British Encyclopedia "Britannica," the oldest historical encyclopedia in the world.

Execution by impalement:

It is considered one of the most horrific and strange methods in the history of execution, where the condemned is tied to a long stake and lifted to be thrust towards it, piercing his body, leading to slow death and severe agony.

Execution by Catherine wheel:

It was used in Europe during the Middle Ages, where the condemned is tied to a wheel containing an iron rod, then the wheel is rotated against the direction of the rod to break the person's bones and cause death in a horrific way.

Execution by a thousand cuts:

It is considered one of the strangest execution methods in ancient China, and one of the most brutal in history, where a part of the condemned’s flesh is cut daily for several days, and they are given opium to keep them alive as long as possible before dying from wounds and pain.

Execution by snake bite:

In ancient India, snake bites were used as a method of execution, where venomous snakes were placed on the condemned's body, leading to death from the toxins.

Execution by hanging criminals for crocodiles:

In ancient Egypt, criminals were tied to trees and left to be attacked by crocodiles and other animals, causing a horrific death.

Execution by beheading:

It is considered one of the oldest and most famous execution methods in the Middle Ages, and was used in many countries, where the condemned’s head was cut off using an axe, sword, knife, or guillotine after the final verdict was announced, while the severed heads were hung on the walls of the Tower of London in Britain.

Burning:

Execution by burning is one of the oldest methods used in the world, common in the Middle Ages and used to execute thousands of Christians in the days of the Roman state. The victim is tied to a wooden post and placed over flammable materials and set on fire.

Crushing:

The crushing method was widespread in different parts of the world. In Asian countries, crushing was usually done using elephants, and this method was used for more than 4000 years.

Boiling:

It is considered one of the most brutal methods of execution, where the offender is placed in a huge pot containing a boiling liquid, such as water, oil, acid, or tar.