Since May 22, 2017, six terrorists from Yorkshire have been jailed, with a further five defendants awaiting court appearances later this year.
Here the Yorkshire Post takes a look at the evil crimes and plots that could have devastated our communities.
May 2018: The banned Neo-Nazi group member from Castleford
Not only did Wayne Bell, 37, post an image on a Russian social media site showing a man being hung by a rope with a Star of David on his forehead, but he also described Jewish people as "destructive and vile".
Bell, of Mount Walk, Castleford, was also behind hate-filled graffiti.
A Crown Prosecution Services spokesman told Leeds Crown Court how in August 2016, Bell wrote in a social media post "The only way," below a photo of a police officer's foot raised above the head of an unarmed black man, lying on the ground.
The spokesman said that in late 2016 he posted a number of messages on Twitter continuing his campaign of stirring up hatred against Jewish and black people.
Bell was a prominent member of National Action before its was banned more than two years ago and he featured in two posters used in a recruitment campaign.
The spokesman said 13 videos were found on Bell's mobile phone and featured an unseen man - believed to be Bell - directing others who were daubing anti-Semitic graffiti, including swastikas and references to the Holocaust.
A rucksack found at his workplace in Leeds contained National Action stickers.
Bell pleaded guilty at Leeds Crown Court to two counts of stirring up racial hatred and three counts of possession of items with intent to destroy or damage property.
He was jailed for four years and three months.
Detective Chief Superintendent Martin Snowden, Head of Counter Terrorism Policing North East, said: "Activity like this has the potential to both influence vulnerable people and threaten the stability of our communities by inciting hatred and threatening public safety and security.
"We will not tolerate any action which attempts to undermine or divide our communities and will continue to counter extremism and terrorism in all its forms."
July 2018: The Nazi teen from Mexborough who made a bomb in his own bedroom
Jack Coulson, 19, made a pipe bomb in his Nazi memorabilia-filled bedroom.
Coulson, of Mexborough, also downloaded The Big Book of Mischief to his phone after allegedly boasting about wanting to kill a female MP following MP Jo Cox's death.
Leeds Crown Court heard how the 60-page manual provided information on the chemicals needed to build weapons, as well as practical advice on detonators, handguns and rockets.
Investigators also found Coulson had researched Timothy McVeigh, the American terrorist who carried out the 1995 Oklahoma City bombing which killed 16 people.
David Temkin, prosecuting, said Coulson had "an active interest in far-right political views and violence", and during a police interview described Adolf Hitler as his "leader".
At his previous trial, jurors heard Coulson, who lived in Bradford at the time, had praised the killer of MP Jo Cox and was a member of the "secretive neo-Nazi" group National Action.
Det Supt Simon Atkinson, of Counter Terrorism Policing North East, said: "While no evidence was found to suggest Coulson was planning to act on this information, the combination of this material and his ideology is very concerning."
Coulson was sentenced to four years and eight months in youth custody.
July 2018: The North Yorkshire teenagers who plotted school massacre
School boys Thomas Wylie and Alex Bolland plotted to gun down innocent classmates in a replica version of the 1999 Columbine massacre.
Wylie and Bolland were said to have "hero-worshipped" Dylan Klebold and Eric Harris, the teenagers who took up arms and killed 13 people at the Columbine High School in Colorado before taking their own lives.
The two boys, who were just 14 at the time, were so serious about carrying out their own version of the attack at their school in Northallerton, North Yorkshire, that they had drawn up a “hit-list” of targets - which included students who had bullied and wronged them, as well as teachers.
During their trial, prosecutors told how conversations about the plan went beyond the realms of fantasy, as the teenagers downloaded bomb-making manuals, researched weapons online and warned friends about what was to come.
The older of the plotters, who has been described as the leader and main instigator, discussed his motivations for the plan in a diary which espoused what jurors were told was his “twisted ideology”.
The inside cover of the book, which was recovered from the teenager’s home in October 2017, apologises for either committing “one of the worst atrocities in British history” or killing himself.
The journal also features a page of “stuff we need” to execute the plan, including napalm, firearms and pipe bombs.
In a secret hideout in Catterick Garrison, the same boy had kept a rucksack filled with screws, boards and flammable liquid, which prosecutors suggested were instruments for making an explosive device which was to be part of the killing.
Prosecutors told how the boy had also warned his then-girlfriend that he wanted to murder her parents, so that he could run away with her and become a “natural born killer”.
When his co-conspirator lost interest in carrying out the plot, the older teenager described the girlfriend as “his Dylan Klebold” and repeatedly asked her to access her father’s shotguns.
He and his co-defendant were interviewed by police after the younger of the pair, who had suffered bullying at school, messaged a female friend in September 2017 to tell her about the plan.
When she asked if he was joking, he responded: “No. No-one innocent will die. We promise.”
The next day, the same boy made “clear and unvarnished confessions” to a teacher and to police officers, claiming that his targets were “infecting the gene pool” and that he and his friend were doing a “service to society”.
Both were interviewed by North Yorkshire Police, who later accepted that they “did not meet those standards that are expected” in the way they dealt with the boys.
Leeds Crown Court heard how the older defendant had started researching the Columbine massacre again within minutes of the officers leaving, despite having denied plans for the attack.
He was eventually arrested after his hideout was discovered by officers on October 22 2017, with the younger boy voluntarily attending a police station with his mother three days later.
They both stood trial, but were found guilty of conspiracy to murder by a jury in May, with the older boy additionally being convicted of unlawful wounding.
The older boy was given a 12-year custodial sentence, while the younger was given 10 years.
December 2018: The Leeds student who encouraged terrorism and posted threats against Prince Harry
Polish student Michael Szewczuk, 19, was living in Leeds when he and his associate Oskar Dunn-Koczorowski encouraged terrorism in online messages to a group which posted threats against the Duke of Sussex.
The pair were members of SonnenKreig Division, a British arm of an American neo-Nazi terrorist group said to be responsible for the murder of a gay teenager.
The group posted a picture of Prince Harry set against a swastika, with a gun pointed to his head and the slogan "See ya later, race traitor!".
Szewczuk also had terrorist documents including the White Resistance Manual, a Practical Guide to the Strategy and Tactics of Revoultion, Anarchist Cookbook; a copy of a document called the al-Qaeda Manuel and another called How to Survive in the West - a Mujahid's Guide 2015, produced by an ISIS supporter.
The pair were arrested on December 6 in relation to material posted to three accounts on the social media account site.
The primary purpose of all three sites was said to be promoting the ideology and activity of a group known as SonnenKrieg Division (SKD).
Szewczuk pleaded guilty to encouraging terrorism, disseminating terrorist publications and possessing terrorist material.
He will be sentenced on June 17.
January 2019: Sheffield terrorists had link to Manchester bomber and sent money to Syria
Abdurahman Kaabar and Badroddin Kazkaz, both from Sheffield sent money to Syria to fund terrorism.
Kaabar also told a friend he had "close family links" to Manchester Arena bomber Salman Abedi.
The pair transferred money to Kaabar's brother after he left the UK to "engage in violent Jihadi activity".
A jury at Sheffield Crown Court were shown a number of Whatsapp messages sent by Kaabar to a number of people including his brother.
In one message Kabaar, a former dental student, said: “Don't worry about me. I am da ISIS bro Allahu Akbar. I hope you ready for dis ride brow, it guna b an explosive one g trust me...explosive."
During another communication with the same friend, Kaabar claimed 'we need an Islamic state' and ‘da Islamic state is cumin’.
Kaabar, 24, of Upperthorpe, had also been found with documents giving instructions for knife attacks and bomb making.
He was found guilty of two counts of terrorist fundraising following an earlier trial. He also pleaded guilty to another 15 offences concerning the disseminating of terrorist publications and possessing material likely to be useful to a person committing or preparing an act of terrorism.
Kazkaz, 23, of Heeley, pleaded guilty to terrorist fundraising.
Kaabar was jailed for eight years, with Kazkaz sentenced to four years.
After Kaabar’s trial, Head of Investigations at Counter Terrorism Policing North East, Detective Superintendent Simon Atkinson, said: “Kaabar had a radical mindset and an active interest in extremism. He was not only in possession of terrorist material, he was also sharing it and encouraging others to carry out terrorist activity."
March 2019: Leeds man "had instruction manuals on killing techniques"
Pawel Golaszewski, 33, is accused of possessing instruction manuals on making weaponry and killing techniques.
Golaszewski, from Leeds, is facing six counts under the Terrorism Act.
He is charged with possession of a document or record containing information of a kind likely to be useful to a person committing or preparing an act of terrorism.
The charges allege that, on February 23 in Leeds, Golaszewski had copies of 21 Silent Techniques Of Killing by Master Hei Long, The Anarchist Cookbook and The Big Book Of Mischief.
He will appear at the Old Bailey for a plea and case management hearing on June 28.
A provisional trial date of September 2, has been set.
April 2019: Bradford man charged with having terror instruction manuals
Umar Hafeez, 37, of Heaton Road in Bradford, is charged with 13 counts of possessing a record containing information useful to terrorism.
He is accused of possessing records with titles include Step By Step Knifemaking, You Can Do It!
Other files he is accused of possessing include The Anarchist Cookbook by The Jolly Roger, Put 'Em Down, Take 'Em Out and How To Survive In The West.
Hafeez is charged with 13 counts of possessing a record of a kind likely to be useful to a person committing or preparing an act of terrorism, contrary to section 58 of the Terrorism Act 2000.
He is due to appear at Leeds Crown Court on September 20, for a plea and case management hearing.
A provisional trial date has been set for October 21.
May 2019: Bradford teenager planned to go on rampage and "kill many" after making bomb
A 16-year-old boy from Bradford, who cannot yet be named for legal reasons, researched bomb making and constructed a device that could have been "a viable CO2 bomb", before threatening to "go on a rampage" and "kill many people".
He also told students a year previously that he was going to carry out a school shooting and had praised Adolf Hitler, Leeds Crown Court heard.
Prosecutors said the boy had developed an interest in extremist far-right ideology and his searches on the internet had become "progressively dark", accessing videos and information about murder, torture and mutilation.
The teenager first came to the notice of police in 2016 and a referral to Prevent was made in 2017. Despite the hard work of Prevent officers and other safeguarding professionals over an extended period, the boy’s behaviour continued to be of serious concern and last summer the decision was made to arrest him.
When officers searched his home they found, in his bedroom, a device constructed in line with instructions around the manufacture of a CO2 bomb. Thankfully, the device was not fully completed and was not classed as viable.
Analysis of the boy’s online activity showed extensive research around bomb-making, searches about attacks on Muslims, and a wide range of videos showing death, mutilation and torture; clearly showing an escalating interest in violence and extreme ideology.
Detective Chief Superintendent Martin Snowden, the Head of Counter Terrorism Policing North East said: “This is a disturbing case of a teenager who developed an alarming interest in extremist ideology, violence, firearms and explosives. He has spent considerable time alone on the internet and has intentionally accessed the ‘dark web’.
“His fascination with violence and death is particularly concerning given his age and vulnerability. Young people can be susceptible to the negative influences online and we urge people to have the confidence to report worrying attitudes or behaviour.
The boy will be sentenced at Leeds Crown Court next month.