Isaac I Komnenos (or Comnenus) (Greek: Ισαάκιος A' Κομνηνός, Isaakios I Komnēnos) (c. 1007 – 1061) was Byzantine Emperor from 1057 to 1059, and the first reigning member of the Komnenos dynasty. His brief reign saw an attempt to restore the Byzantine Empire’s military capability and reputation.

He was the son of Manuel Erotikos Komnenos, the strategos autokrator of the East under Emperor Basil II who in 978 defended Nicaea against Bardas Skleros, and one of his two wives, whose names are unknown, and who on his deathbed in 1020 commended his two surviving sons Isaakios and Ioannes to the emperor's care. Basil had them carefully educated at the monastery of Stoudion, and afterwards advanced them to high official positions. He also had an older son, Nikephoros, who died in 1026, and a daughter, born in 1012 and married around 1031 to Michael Dokeianos, Catepan of Italy, deceased in 1050. It is said that their name was derived from the city of Komne, near Philippopolis, where they were landowners, and that they were of Armenian ancestry from Paphlagonia, which is supported by the use of the name Manuel instead of Emmanouel.

Isaac II Angelos (or Angelus) (Greek: Ισαάκιος Β’ Άγγελος, Isaakios II Angelos) (September 1156 – January 1204) was Byzantine Emperor from 1185 to 1195, and again from 1203 to 1204.

His father Andronikos Dukas Angelos, a military leader in Asia Minor (c. 1122 – aft. 1185), married bef. 1155 Euphrosyne Kastamonitissa (c. 1125 – aft. 1195). Andronikos Dukas Angelos was the son of Konstantinos Angelos, Admiral of Sicily (c. 1085 – aft. July 1166, son of Manolis Angelos from Philadelphia) and Theodora Komnene (b. 15 January 1096/1097) who was the youngest daughter of Emperor Alexios I Komnenos and Eirene Doukaina. Thus, Isaac was a member of the extended imperial clan.

During the brief reign of Andronikos I Komnenos, Isaac was involved (alongside his father and brothers) in the revolt of Nicaea and Prousa. Atypically, the Emperor did not punish him for this disloyalty, and Isaac remained at Constantinople.

On September 11, 1185, during Andronikos' absence from the capital, the latter's lieutenant Stephanos Hagiochristophorites moved to arrest Isaac. Isaac killed Hagiochristophorites and took refuge in the church of Hagia Sophia. Andronikos, in some ways a capable ruler, was hated for his cruelty and his efforts to keep the aristocracy obedient. Isaac appealed to the populace, and a tumult arose which spread rapidly over the whole city. When Andronikos arrived he found that during his absence he had lost popular support, and that Isaac had been proclaimed emperor. Andronikos attempted to flee by boat but was apprehended. Isaac handed him over to the people of the City, and he was killed on 12 September 1185.

Isaac ( /ˈaɪzək/;Hebrew: יִצְחָק, Modern Yitsẖak Tiberian Yiṣḥāq, ISO 259-3 Yiçḥaq, "he will laugh"; Yiddish: יצחק, Yitskhok; Ancient Greek: Ἰσαάκ, Isaak; Latin: Isaac; Arabic: إسحاق‎ or Arabic: إسحٰق‎ʼIsḥāq) as described in the Hebrew Bible, was the only son Abraham had with his wife Sarah, and was the father of Jacob and Esau. Isaac was one of the three patriarchs of the Israelites. According to the Book of Genesis, Abraham was 100 years old when Isaac was born, and Sarah was beyond childbearing years.

Isaac was the only biblical patriarch whose name was not changed, and the only one who did not leave Canaan. Compared to those of Abraham and Jacob, Isaac's story relates fewer incidents of his life. He died when he was 180 years old, making him the longest-lived patriarch.

The anglicized name Isaac is a transliteration of the Hebrew term Yiṣḥāq which literally means "He laughs/will laugh."Ugaritic texts dating from the 13th century BCE refer to the benevolent smile of the Canaanite deity El. Genesis, however, ascribes the laughter to Isaac's parents, Abraham and Sarah, rather than El. According to the biblical narrative, Abraham fell on his face and laughed when Elohim imparted the news of their son's eventual birth. He laughed because Sarah was past the age of childbearing; both she and Abraham were advanced in age. Later, when Sarah overheard three messengers of the Lord renew the promise, she laughed inwardly for the same reason. Sarah denied laughing when Elohim questioned Abraham about it.

Balian of Ibelin (French: Balian d'Ibelin; early 1140s–1193) was an important French noble in the crusader Kingdom of Jerusalem in the 12th century.

Balian was the youngest son of Barisan of Ibelin, and brother of Hugh and Baldwin. His father, a knight in the County of Jaffa, had been rewarded with the lordship of Ibelin after the revolt of Hugh II of Le Puiset. Barisan married Helvis of Ramla, heiress of the wealthy lordship of Ramla. Balian's name was also Barisan, but he seems to have adapted the name (found in Tuscany and Liguria) to the Old French "Balian" c. 1175–76; he is sometimes known as Balian the Younger or Balian II when his father is also referred to as Balian. He is also called Balian of Ramla or Balian of Nablus. In Latin his name appears variously as Balian, Barisan, Barisanus, Balianus, Balisan, and Balisanus. Arabic sources call him Balian ibn Barzan', which translates "Balian, son of Barzan (or Barisan). His precise year of birth is unknown, but he was of the age of majority (usually 15) by 1158, when he first appears in charters, having been described as under-age ("infra annos") in 1155.