There are two Niobes in Greek Myth: one was the daughter of Tantalus, and a prideful mother whose children were slain by Apollo and Artemis. The other, less well-known, was the daughter of Phorenus, and the mother, by Zeus of Argus – for whom the city of Argos was named.
It should be noted also, that thus Argus was not any of the other figures in Greek Myth named either Argos or Argus – he was not the shipwright who built the Argo, nor the son of Jason and Medea named for that shipwright. Neither was he a legendarily faithful dog whose master was Odysseus, nor the hundred-eyed giant known as Argus Panoptes. He was just this guy, who happened to be the third king of Argos, and the first child Zeus had by a mortal woman. He would have lots of half-siblings, mostly posthumously.
By William Henry Goodyear, A History of Art: For Classes, Art-Students, and Tourists in Europe, A. S. Barnes & Company, New York, 1889. Page 158. Scanned by Dave Pape., Public Domain, Link
As mentioned in:
When You Sleep — Cake
One can’t help thinking that Leda knew more than she was telling. Legendarily one of the most beautiful women in ancient Greece, this queen of Sparta dallied with a swan (who, it turned out, was actually Zeus in disguise), and gave birth to perhaps the only woman to be more beautiful than her: Helen (later of Troy).
In fact, she gave birth to four children, two sets of twins. Half of them were mortal, the children of Tyndareus (her human husband), and half were half-divine, the children of Zeus. Which children are descended from which father is inconsistent across the various tellings of the myth, although a majority of versions record that Helen was half-divine (accounting for her legendary beauty).