The identification of the “oldest terrorist group” depends heavily on the definition of terrorism, as the term itself is modern (emerging during the French Revolution’s “Reign of Terror” in the late 18th century)

. 

Scholars generally categorize groups into ancient/pre-modern and modern terrorism. 

Ancient and Pre-Modern Groups

Using a broader definition of politically motivated violence and intimidation, the roots of terrorism are often traced to ancient groups: 

• Sicarii Zealots (1st Century AD): This Jewish splinter group, or “dagger men,” operated in the Roman province of Judea. They used short daggers hidden under cloaks to assassinate Jewish collaborators with Roman rule, often in crowded places like large festivals, before disappearing into the public.
• The Assassins (Hashshashin) (Late 11th Century): An offshoot of Isma’ili Shia Muslims, this small militia seized fortresses in Persia and specialized in the targeted assassinations of Seljuk and Fatimid rulers, governors, and military commanders to achieve political goals.
• The Kharijites (7th Century AD): In the Islamic world, this early sect practiced takfir, which allowed them to justify killing those they deemed apostates or heretics for political ends, making them the first group in Islamic history whose members were described with similar concepts to ‘terrorists’. 

Modern Terrorist Groups

The first organizations to use modern terrorist techniques, such as the use of powerful explosives to sow widespread fear among a general population for political gains (rather than just political assassination), emerged in the mid-to-late 19th century: 

• Irish Republican Brotherhood (IRB) / Fenian Brotherhood (Founded 1858): Arguably one of the earliest modern groups, the IRB and its offshoot were revolutionary Irish nationalist groups that carried out attacks in England, including the “Fenian dynamite campaign” in the 1880s, with the express aim of creating panic and achieving an independent Irish republic.
• Narodnaya Volya (“People’s Will”) (Founded 1878): This revolutionary anarchist group in Russia was the first to make widespread use of dynamite. They targeted high-ranking officials, including the assassination of Tsar Alexander II in 1881, hoping to inspire a mass rebellion against the Tsarist autocracy.
• Ku Klux Klan (KKK) (Founded 1865): Formed in the post-U.S. Civil War South by Confederate veterans, the first iteration of the KKK used violence, lynching, and intimidation to oppress African Americans and supporters of Reconstruction. A federal grand jury determined the KKK to be a “terrorist organization” in 1870. 

Ultimately, while the tactic of terror has ancient roots, the concept of an organized “terrorist group” using modern methods is a phenomenon of the last two centuries. 

The identity of the “oldest terrorist” is subjective, as the definition of terrorism is widely disputed and has evolved significantly over time

. The term itself was first used during the French Revolution’s “Reign of Terror” in the late 18th century to describe state-sponsored violence. 

Depending on how “terrorism” is defined (e.g., targeting civilians, political motivation, non-state actor status), different groups and individuals have been cited as the earliest examples:

• Ancient Groups: Some scholars trace the roots of terrorism to the Sicarii Zealots, a 1st-century Jewish group that used daggers to assassinate fellow Jews suspected of collaboration with Roman rule in ancient Judea.
• Early Modern Era: Others point to groups like the Hashshashin (Assassins), a Shiite Muslim sect active from the 11th to 13th centuries that targeted political leaders, or the participants in the Gunpowder Plot of 1605 in England.
• Modern Terrorism: In the modern sense (systematic violence by non-state actors against the state), the Russian revolutionary group Narodnaya Volya (People’s Will), founded in 1878, is often considered the first to use modern terrorist techniques like targeted killings and dynamite to sow fear. The first person in this context is often recognized as social revolutionary Vera Zasulich, who shot a Russian governor in 1878 to protest state repression. 

Ultimately, there is no single individual or group universally recognized as the oldest terrorist, as the label depends heavily on the specific criteria used for the term.

The identification of the “oldest terrorist group” depends heavily on the definition of terrorism, as the term itself is modern (emerging during the French Revolution’s “Reign of Terror” in the late 18th century)

. 

Scholars generally categorize groups into ancient/pre-modern and modern terrorism. 

Ancient and Pre-Modern Groups

Using a broader definition of politically motivated violence and intimidation, the roots of terrorism are often traced to ancient groups: 

• Sicarii Zealots (1st Century AD): This Jewish splinter group, or “dagger men,” operated in the Roman province of Judea. They used short daggers hidden under cloaks to assassinate Jewish collaborators with Roman rule, often in crowded places like large festivals, before disappearing into the public.
• The Assassins (Hashshashin) (Late 11th Century): An offshoot of Isma’ili Shia Muslims, this small militia seized fortresses in Persia and specialized in the targeted assassinations of Seljuk and Fatimid rulers, governors, and military commanders to achieve political goals.
• The Kharijites (7th Century AD): In the Islamic world, this early sect practiced takfir, which allowed them to justify killing those they deemed apostates or heretics for political ends, making them the first group in Islamic history whose members were described with similar concepts to ‘terrorists’. 

Modern Terrorist Groups

The first organizations to use modern terrorist techniques, such as the use of powerful explosives to sow widespread fear among a general population for political gains (rather than just political assassination), emerged in the mid-to-late 19th century: 

• Irish Republican Brotherhood (IRB) / Fenian Brotherhood (Founded 1858): Arguably one of the earliest modern groups, the IRB and its offshoot were revolutionary Irish nationalist groups that carried out attacks in England, including the “Fenian dynamite campaign” in the 1880s, with the express aim of creating panic and achieving an independent Irish republic.
• Narodnaya Volya (“People’s Will”) (Founded 1878): This revolutionary anarchist group in Russia was the first to make widespread use of dynamite. They targeted high-ranking officials, including the assassination of Tsar Alexander II in 1881, hoping to inspire a mass rebellion against the Tsarist autocracy.
• Ku Klux Klan (KKK) (Founded 1865): Formed in the post-U.S. Civil War South by Confederate veterans, the first iteration of the KKK used violence, lynching, and intimidation to oppress African Americans and supporters of Reconstruction. A federal grand jury determined the KKK to be a “terrorist organization” in 1870. 

Ultimately, while the tactic of terror has ancient roots, the concept of an organized “terrorist group” using modern methods is a phenomenon of the last two centuries.