ORTHODOX KILLER KINGS AND QUEENS:
The murderous violence of Catholicism and Orthodoxy take generally two forms.
1) The Catholics have historically liked to make a show of their massacres and executions to use mafia like (and Roman Empire like) fear tactics
2) The Orthodox have tended to instead murder and persecute people more covertly, like imprisoning hundreds of thousands over the years, subjecting them to more secretive tortures, including starvation, cold dark dank conditions, lack of clothing, visitors, medical care and visitations, isolation and outright torture.
When compiling a list of rulers and royalty who were Orthodox and committed such atrocities, we realise the Catholics have their own, like Bloody Mary. This of course brings to light that not only do Catholics have a long list of so called apostolic bishops that the Orthodox say are false, but also a massive list of saints and monarchs the Orthodox do not view as true believers either.
The Orthodox have a special list of such murderous people called "Saints Equal to the Apostles" who specialised in murder, fear tactics, and/or imprisoning anyone not converting to Orthodoxy.
LIST OF ORTHODOX MURDERERS / IMPRISONERS:
It is very important to include the fact that Orthodoxy cunningly makes several kings of the old testament into "saint". In the old covenant, or Law of Moses, killing was certainly permitted, and unwary Orthodox "laity" do not understand therefore that making them into so called "saints" is a crafty ploy to hide the fact in the new and better covenant (Heb 8) of the Law of Christ (Gal 6:2) killing other people is forbidden by Jesus.
Saint King David
Saint Josiah of the southern Kingdom of Judah
They are named as saints of the Old Testament by the Orthodox Church, as numerous calendars, services for their intercession, and the custom of naming them patron saints attest. Some heterodox, however, do not recognise them as saints because they lived before the time of Christ.
KILLER CHRISTIAN KINGS AND QUEENS
MADE SAINTS BY ORTHODOXY.
(under construction - I will be mostly looking for monarchs Orthodoxy view as "saints" who imprisoned people or killed them or persecuted them for not being Orthodox, like many of their so called "saints equal to the apostles". It will take some time for me to filter through lists of proposed kings and queens to isolate the most blood thirsty and tyrannical Orthodox rulers.)
Remember all the killer monarchs that predate thee 1054 schism, if not seen as saints in Orthodoxy, are still supposed to be Christian rulers by Orthodoxy.
1) Abgar V of Edessa, the first Christian monarch in history, holding the Image of Edessa .
2) Abgarus of Edessa, King of Osroene  (Orthodox).
3) Aethelberht of Kent (Catholic, Orthodox).
4) Aethelberht II of East Anglia (Catholic, Orthodox).
5) Alexander Nevsky (Orthodox).
6) Alfred the Great of Wessex, died 26 October 899 (Anglican),
7) Amadeus IX, Duke of Savoy (Catholic).
8) Andrey Bogolyubsky, first Grand Prince of Vladimir (Orthodox).
9) Archil of Kakheti, martyr (Orthodox).
10) Ashot I of Iberia, martyr (Orthodox).
11) Boris I of Bulgaria (Orthodox).
12) Canute IV of Denmark, in Danish "Knud 4. den Hellige" (Catholic).
13) Charles I of England, martyr, died 30 January 1649 (Anglican).
14) Charles I, Count of Flanders, known as "St. Charles the Good", in French "Charles le Bon", in Dutch "Karel de Goede" (Catholic).
15) Constantin Brancoveanu, King of Wallachia (Orthodox).
16) Constantine, King of Dumnonia, martyr (there is confusion regarding his identity).
17) Constantine I, Roman Emperor, died 337, known as "Constantine the Great" and "Constantine, Equal-to-the-Apostles" ("Κωνσταντίνος Α' Ἰσαπόστολος") (Byzantine Catholic, Lutheran, and Orthodox).
18) Constantine IV, Roman Emperor, died 685, known as "Constantine the New" (Orthodox).
19) Constantine XI, Roman Emperor, died 1453, known as "Constantine XI Palaiologos", "The Marble Emperor", "The Last Roman Emperor"; not officially recognized by either the Byzantine Catholic or Orthodox churches, he is popularly regarded in both as the national patron saint, i. e., "Ethnomartyr" ("Ἐθνομάρτυρας"), meaning "national martyr" (unofficial).
20) Cormac mac Cuilennáin, King of Munster (Catholic, Orthodox).
21) Dagobert II, martyr, Merovingian king of Austrasia, son of St. Sigebert III (Catholic).
22) David I of Scotland, son of St. Margaret of Scotland (see under "Other royalty and nobility" below), in Gaelic "Naomh Daibhidh" (Catholic).
23) David IV of Georgia, known as "David the Builder" (Orthodox).
24) David of Trebizond (Orthodox).
25) Demetre I of Georgia (Orthodox).
26) Demetre II of Georgia, martyr, known as "Demetre the Self-Sacrificer" (Orthodox).
27) Eberhard, Duke of Friuli, son-in-law of Frankish emperor Louis the Pious and ancestor of all contemporary royals (Catholic).
28) Edmund the Martyr, King of East Anglia (Catholic, Orthodox).
29) Edward the Confessor, King of England (Catholic, Orthodox).
30) Edward the Martyr, King of England (Catholic, Orthodox).
31) Edwin of Northumbria (Catholic, Orthodox).
32) Eric IX of Sweden, martyr, died 18 May 1161, Pope Alexander III forbid his cultus in 1172, and he was never canonized, but he is revered as a patron saint of Sweden, in Swedish "Erik den helige" and "S:t Erik" (unofficial).
33) Fedelmid mac Crimthainn, King of Munster (Catholic, Orthodox).
34) Ferdinand III of Castile, known as "Ferdinand III the Saint", in Spanish "San Fernando" and "Fernando III el Santo" (Catholic).
35) Guntram, Merovingian king of Burgundy (Catholic).
36) Henry II, Holy Roman Emperor, husband of Cunigunde of Luxemburg (see under "Other royalty and nobility" below), known as "St. Henry II", in German"Heinrich II. der Heilige" ("Henry II the Holy") (Catholic).
37) Hermenegild of the Visigoths (Catholic, Orthodox)
38) Humbert III of Savoy (Catholic).
39) Jadwiga of Poland, known as "St. Hedwig of Poland" and "St. Hedwig, Queen of Poland", in Polish "Św. Jadwiga Królowa Polski" (Catholic).
40) John III, Roman Emperor, died 1254, known as "John the Merciful" and "John III Doukas Vatatzes" (Orthodox).
41) John IV, Roman Emperor, died 1305, known as "John IV Laskaris" and "John IV Doukas Laskaris" (Orthodox).
42) Justinian I, Roman Emperor, died 565, known as "Justinian the Great" (Lutheran, Orthodox).
43) Justinian II, Roman Emperor, died 711, known as "Justinian Rhinotmetos" ("ὁ Ῥινότμητος", "the slit nosed") (Orthodox).
44) Ladislaus I of Hungary, in Hungarian "Szent László" (Catholic).
45) Lazar Hrebeljanović, Knez ("Prince" or "Duke") of Serbia, died 1389, known as "Tsar Lazar", canonized by the Serbian Orthodox Church as "Свети Косовски Великомученик кнез Лазар" ("Holy Great-Martyr of Kosovo Prince Lazar"), known as "Свети Цар Лазар" ("Holy Tsar Lazar") (Serbian Orthodox Church).
46) Leo I, Roman Emperor, died 474 (Orthodox)  .
47) Leopold III, Margrave of Austria (Catholic).
48) Luarsab II of Kartli, martyr (Orthodox).
49) Louis IX of France, in French "St. Louis" (Catholic).
50) Ludwig IV of Thuringia, husband of Elisabeth of Hungary (see under "Other royalty and nobility" below), not canonized but revered as a saint in Thuringia, in German "Ludwig IV., der Heilige" ("Ludwig IV the Holy") (unofficially Catholic).
51) Manuel II, Roman Emperor, died 1425, known as "Manuel I Palaiologos" and "Manuel the Monk" (Orthodox).
52) Marcian, Roman Emperor, died 457 (Orthodox).
53) Michael of Tver, martyr, Grand Prince of Vladimir (Orthodox).
54) Mirian III of Iberia .
55) Neagoe Basarab, King of Wallachia  .
56) Nicholas II of Russia, Czar of Russia, the Russian Orthodox Church Outside Russia canonized him in 1980 as a saint and martyr, the synod of the Russian Orthodox Church canonized him as a saint and passion bearer on 14 August 2000, in Russian "Царь-Мученик Николай II" ("Tsar-Martyr Nicholas II") and "Святой Страстотерпец Царь Николай II" ("Holy Passion-Bearer Tsar Nicholas II") (Orthodox).
57) Nikephoros II, Roman Emperor, died 969, known as "Nikephoros II Phokas" (Orthodox).
58) Olaf II of Norway, known as "St. Olav" and "St. Olave", in Old Norse "Oláfr hinn helgi", in Bokmål "Olav den hellige", in Nynorsk "Heilag-Olav" (Catholic, Orthodox).
59) Oswald of Northumbria, died 642, martyr (Catholic, Orthodox) .
60) Peter I of Bulgaria (Orthodox) .
61) Sigebert III, Merovingian king of Austrasia, father of St. Dagobert II (Catholic).
62) Sigismund of Burgundy (Catholic).
63) Solomon II of Imereti (Georgian Orthodox) .
64) Stephen I of Hungary, known as "St. Stephen of Hungary", in Hungarian "Szent István király" (Catholic) .
65) Stephen the Great, King of Moldavia, repaused 2 July 1504, known as the "Athlete of Christianity", a patron saint of Moldavia, in Romanian"Dreptcredinciosul Voievod Ştefan cel Mare şi Sfânt" .
66) Tamar of Georgia, died 1213, known as "Holy Righteous King Tamar" in the Georgian Orthodox Church (Orthodox) .
67) Theodosius I, Roman Emperor, died 395, known as "Theodosius the Great" (Orthodox) .
68) Theodosius II, Roman Emperor, died 450, known as "Theodosius the Younger"
and "Theodosius the Calligrapher" (Orthodox).
69) Tiridates III of Armenia, revered as a saint in the Armenian Church .
70) Vakhtang I of Iberia (Georgian Orthodox) .
71) Vakhtang III of Georgia (Georgian Orthodox).
72) Vladimir I of Kiev, first Christian ruler of Kiev, in the Russian Orthodox Church his title denotes "equal to the Apostles", in Russian "Владимир Святой", in Ukrainian "Володимир Святий" and "Святий рівноапостольний князь Володимир" ("Saint Equal-to-the-Apostles Duke Volodymyr") (Orthodox)
73) Wenceslaus I, Duke of Bohemia, died 28 September 935, martyr, patron of the Czech Republic, in Czech "Svatý Václav", in German "Heilige Wenzel" (Catholic, Orthodox)
74) William of Gellone, Count of Toulouse (Catholic).