Dukat lays injured after an assassination attempt
Assassination was the act of murdering an important individual for political or ideological purposes. Those who carried out assassinations were known as assassins.
Assassination was a common practice utilized in the mirror universe to secure promotions or rid oneself of those who might wish to do the same to you. Sylvia Tilly became captain of the ISS Discovery through assassinating the previous captain, who had been recovering from the Crestian flu. Danby Connor attempted the same with Michael Burnham, not realizing that she was actually her prime universe counterpart, but failed and was killed instead. (DIS: "Despite Yourself") In 2267, when Captain James T. Kirk, accidentally transported to that universe, refused to fire on the Halkans for denying the Terran Empire dilithium, Ensign Pavel Chekov attempted to assassinate him. He stated that nobody would question the assassination of a captain who had disobeyed prime orders of the Empire. Later, on researching the history of that universe, Kirk discovered that his counterpart had advanced to the command of the ISS Enterprise by assassinating Captain Christopher Pike. (TOS: "Mirror, Mirror")
On Klingon vessels, it was considered the duty of a lower-ranked officer to assassinate their next higher ranking officer if they had become weak and unable to perform. (TNG: "A Matter Of Honor")
Klingon Emperor Reclaw of the Second Dynasty was assassinated by General K'Trelan. (DS9: "You Are Cordially Invited")
In 2293, Captain Kirk and Doctor McCoy were sent to Rura Penthe after being wrongfully convicted of assassinating Klingon chancellor Gorkon. (Star Trek VI: The Undiscovered Country)
Romulan Proconsul Merrok was assassinated in the 24th century by poison. Elim Garak may have been involved. (DS9: "Broken Link")
As of 2375, Smeet was the only Ferengi Grand Nagus to ever be assassinated in office. (DS9: "Ferengi Love Songs")
In 2365, a conference on Pacifica was almost threatened when two Antideans posed as visiting dignitaries, intending to blow up the area with ultritium hidden in their robes. They were identified by Ambassador Lwaxana Troi and detained. (TNG: "Manhunt")
By 2366, Dukat had survived four assassination attempts during his time as Prefect of Bajor. Timor Landi, Ishan Chaye and Jillur Gueta were executed for an attempt in that year. (DS9: "Things Past", "Waltz")
Over a period of six months in 2366, Alexana Devos had three assassination attempts on her life by the Ansata. (TNG: "The High Ground")
In 2369, the Kohn-Ma claimed responsibility for the assassination of one of the Bajoran First ministers. (DS9: "Past Prologue")
The same year, a Bajoran officer tried to assassinate Commander Benjamin Sisko with a small device he received from Doctor Julian Bashir. All participants were under the influence of the Saltah'na energy spheres. (DS9: "Dramatis Personae")
Also that same year, the Bajoran engineer Neela, who conspired with Vedek Winn Adami, tried to assassinate Vedek Bareil Antos during his visit of the station. (DS9: "In the Hands of the Prophets")
Additionally that same year, the prime minister of Tilonus IV was assassinated, resulting in the collapse of the planet's government and what was described as a state of total anarchy. (TNG: "Frame of Mind")
Kira once told Odo about her past with the Shakaar resistance cell and that she lay down at night and plotted the assassination of men like Gul Darhe'el. (DS9: "Duet")
In 2371, Enabran Tain ordered the assassinations of several former associates, including Garak, who posed potential threats to his return to power. Garak was able to preempt his assassination attempt by the Flaxian Retaya by destroying his own shop. (DS9: "Improbable Cause", "The Die is Cast")
In 2374, the Orion Syndicate attempted to assassinate the Klingon ambassador to Farius Prime at the behest of the Dominion. The plan failed due to the actions of Miles O'Brien. (DS9: "Honor Among Thieves")
Also in 2374, the assassination of Senator Vreenak by Garak led to the Romulan Star Empire joining the war against the Dominion. (DS9: "In the Pale Moonlight")
In late 2375, Luther Sloan and Section 31 duped Julian Bashir into believing they were about to assassinate Tal Shiar Chairman Koval. In reality, they hoped to stop Kimara Cretak from taking Koval's seat on the Continuing Committee. (DS9: "Inter Arma Enim Silent Leges")
In the Julian Bashir, Secret Agent holoprogram, Lady Wantsomore was brainwashed and made to attempt to assassinate the Queen of England. (DS9: "A Simple Investigation")
In 2379, after Praetor Hiren rejected their demands by Commander Suran to forge an alliance with the Remans against the Federation, Senator Tal'aura used a thalaron radiation projector to assassinate the entire Romulan Senate. (Star Trek Nemesis)
During the Pakled Rebelution of 2381 on Pakled Planet, the Emperor of the Pakleds was sucessfully assassinated during a brief conflict, when one of the Pakled rebels managed to stab him in the back. This rebel would crown himself as the new Pakled leader. (LD: "The Spy Humongous")