Saeculum obscurum (Ecclesiastical Latin: [ˈsɛː.ku.lu.m obsˈkuː.rum], "the dark age/century"), also known as the Pornocracy or the Rule of the Harlots, was a period in the history of the papacy during the first two thirds of the 10th century, following the chaos after the death of Pope Formosus in 896 which saw seven or eight papal elections in as many years. It began with the installation of Pope Sergius III in 904 and lasted for 60 years until the death of Pope John XII in 964. During this period, the popes were influenced strongly by a powerful and allegedly corrupt aristocratic family, the Theophylacti, and their relatives and allies. The era is seen as one of the lowest points of the history of the papal office. https://en.wikipedia.org/wiki/Saeculum_obscurum

There have been periods of fraudulent popes and the process of removing them is sometimes called depositions.

I wonder if u/CrusaderPepe has done a lecture on previous Depositions of Fraud Popes. Might be a good topic to study. This is a list of popes killed or martyred. A fraction of them might have been corrupt or worthy of death.

Saint Peter (c. 67), traditionally martyred by upside-down crucifixion[3]

Pope Linus (Saint) (c. 67 – c. 76)[4][5]

Pope Anacletus or Cletus (Saint) (c. 79 – c. 92)[6][4]

Pope Clement I (Saint) (c. 92 – c. 99), thrown into sea with anchor around his neck[4]

Pope Evaristus (c. 99 – c. 108),[4][5] not listed in the Roman Martyrology but executed[7]

Pope Sixtus I (Saint) (c. 119 – c. 128)[4][5]

Pope Telesphorus (Saint) (c. 128 – c. 138)[4][8]

Pope Anicetus (Saint) (155–166), traditionally martyred[4]

Pope Soter (Saint) (166–175), died a martyr [4]

Pope Eleuterus (Saint) (175–189), died a martyr[4]

Pope Victor I (Saint) 189–199, died a martyr[4]

Pope Calixtus I (Saint) (217–222), died a martyr[4]

Pope Urban I (Saint) 222–230, died a martyr[4]

Pope Pontian (Saint) 230–235, condemned to mines in Sardinia and died on island of Tavolara[4]

Pope Anterus (Saint), elected 21 November 235, martyred at hands of Emperor Maximus[4]

Pope Fabian (Saint), elected 10 January 236 and died a martyr during persecution and decapitated by Decius[4]

Pope Cornelius (Saint), elected March 251 and died a martyr June 253[4]

Pope Lucius I (Saint), elected 25 June 253 and martyred 5 March 254[4]

Pope Stephen I (Saint), elected 12 May 254 and martyred 2 August 257[4][1]

Pope Sixtus II (Saint), elected 30 August 257 and martyred 6 August 258[4]

Pope Dionysius (Saint), elected 22 July 259 after year of persecutions and died 26 December 268, martyred[4]

Pope Felix I (Saint), elected 5 January 269 and died 30 December 274, martyred[4]

Pope Eutychian (Saint), elected 4 January 275 and martyred 7 December 283[4]

Pope Caius (Saint), elected 17 December 283 and martyred 22 April 296 but not at hands of his uncle Diocletian[4]

Pope Marcellinus (Saint), elected 30 June 296 and martyred 25 October 10 during persecution of Diocletian[4]

Pope Marcellus I (Saint), elected 27 May 308 after 4-year vacancy and martyred 16 January 309[4]

Pope Eusebius (Saint), elected 18 April 309 and martyred in Sicily 17 August 309.[4][9]

Pope John I (Saint), elected 13 August 523, during the Ostrogothic occupation of the Italian peninsula. Was sent as an envoy by Ostrogoth king Theodoric the Great to Constantinople. Upon return, Theodoric accused John I of conspiracy with the Byzantine empire. Imprisoned and starved to death on 18 May 526.[4]

Pope Martin I (Saint) Elected in 649. Died in exile 16 September 655.

Murdered popes

John VIII (872–882), poisoned and then clubbed to death[10]

Stephen VI (896–897), strangled[11]

Leo V (903), allegedly strangled[12]

John X (914–928), allegedly smothered with a pillow[13]

John XII (955–964), allegedly murdered by the jealous husband of the woman with whom he was in bed[14]

Benedict VI (973–974), strangled[15]

John XIV (983–984), died either by starvation, ill-treatment, or direct murder[16]

https://en.wikipedia.org/wiki/List_of_popes_who_died_violently