The noun aegis, usually embedded in the phrase under the aegis of, means protection, auspices, or sponsorship. It comes from the Ancient Greek aigis, which denoted a shield or armor made from the skin of a goat. So when a Greek poet wrote that a hero was under the aegis of the gods, this meant the hero was under divine protection.
Examples
The Office of Unclaimed Funds, under the aegis of the state comptroller, had set up a table at the Hilton. [New York Times]
Providing aid to Greece and other countries wouldn’t be straightforward, and it is unclear how it could be done under the aegis of the EU. [Wall Street Journal]
The technology that will make this possible is being developed under the aegis of the Semantic Web movement. [American Libraries Magazine]