Orestes
3 of the 7 encyclopedias on this shelf carry an entry for Orestes. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
o-res'tez, in Greek mythology, the son of Agamemnon and Clytemnestra, king and queen of Mycenae. When Agamemnon returned from the Trojan War, Clytemnestra and Aegisthus laid a plan to murder him and his son. They were successful so far as Agamemnon was concerned, but Orestes was saved by his sister Electra, who had him carried secretly to his uncle Strophius. When grown to manhood, Orestes returned to Mycenae and avenged his father's death by slaying both Aegisthus and Clytemnestra. Orestes, though he had been advised by an oracle to take his mother's life, was, in consequence of the deed, driven frantic by the Furies and pursued from land to land. At length he was directed by an oracle to bring from Tauris in Scythia a statue of Artemis, said to have fallen from heaven. Accompanied by Pylades, his cousin, who had been his faithful companion, he went to Tauris. The people of this place were in the habit of sacrificing strangers, who fell in their way, to the goddess. Orestes and Pylades were seized, bound, and borne to the temple. But the priestess of the temple was Iphigenia, Orestes' sister, who had years before been snatched from death on the altar by Artemis. Iphigenia saved the prisoners from death and all three returned to Mycenae. Orestes was at last purified of his sin by Minerva and relieved from the persecution of the Furies. Both Sophocles and Euripides have used this story for the subject of tragedies.
Collier's New Encyclopedia (1921)
in Greek mythology, the son of Agamemnon and of Clytemnestra, the avenger of his father, by becoming the murderer of his mother. For this murder he is relentlessly pursued by the Eumenides or Furies, and only succeeds in appeasing these terrible goddesses by carrying out the instructions of the Delphian oracle to bring back the statue of Diana from Tauris to Argos. Married to Hermione, daughter er of Menelaus, Orestes ruled over his paternal kingdom of Mycenæ, and over Argos, upon the death of its king. Orestes is an important figure in the "Choephori" and the "Eumenides" of Æschylus, the "Electra" of Sophocles, and the "Orestes" and "Iphigenia in Tauris" of Euripides. Scenes from the story of Orestes appear in Greek decorative art.
1000 Classical Characters (1900)
A son of Agamemnon and Clytemnestra . His father was slain by Clytemnestra and Aegisthus, but young Orestes was saved from his mother's dagger by his sister Electra , called by Homer, Laodicea, and was conveyed to the house of Strophius, king of Phocis, who had married a sister of Agamemnon. He was indulgently treated by Strophius, who educated him with his son Pylades. The two young princes formed the most inviolable friendship. When Orestes had arrived at years of manhood he avenged his father's death by killing his mother Clytemnestra.