(Flash Comics v1 005, 1940)
It's another version of the old Order of Assassins, this time as a revival founded by a supposed descendant of Hassan-i Sabbah, the original Assassin of yore, though since he died in 1124 AD there's a decent chance that anybody is his descendant.
Legitimacy aside, this buncha yahoos operates out of a city-fortress called Alamut (but somewhere in the vicinity of Egypt rather than Iran) and is engaged in a somewhat nebulous plot to conquer the world by assassinating various leaders, including that of the very delicious-sounding nation of Frappe. Hawkman foils this scheme with a few well-placed sling bullets, but even though their leaders are killed, the bulk of the organization survives, possibly as part of the next iteration of the Order, whenever that crops up.