Definition of "Dioscuri"

Or, alas, might not one rather attribute it to Diana in the shape of Hunger? To some twin Dioscuri, OPPRESSION and REVENGE; so often seen in the battles of men?

1837, Thomas Carlyle, chapter III, in The French Revolution: A History […], volume I (The Bastille), London: Chapman and Hall, book IV (States-General)

Cæsar, either more ambitious or less confident in his services, raised a new and costly row of columns in front of the Capitol. He built a temple to the Dioscuri, and he charmed the populace with a show of gladiators unusually extensive.

1879, James Anthony Froude, chapter XI, in Cæsar: A Sketch‎, page 108