Board Thread:Questions and Answers/@comment-11220539-20160214210504/@comment-26066818-20160215185444

1) The creation of SHIELD and Hydra is currently in a "fuzzy" state (see this thread: http://marvel.wikia.com/wiki/Thread:858411). Classically speaking, SHIELD was created in the Modern Era, shortly before FF #1 on the sliding timescale at the earliest. Recent comics have indicated SHIELD has been around since the 1960's, Marvel-Time, as well.

Baron Strucker was involved in the creation/cultivation of Hydra even before the end of World War II. By 1961, by any time scale, Strucker was definitely associated with Hydra, or what would become Hydra, already.

Leviathan was also active before the Zodiac Event. The Event is what led to Overwinter, and Leviathan was definitively active prior to that breakdown.

2) I cannot cite a specific issue off the top of my head where the exact phrase "Council of Nine" was used, but that was definitely the ruling body of the Secret Empire in the 90's. That hierarchy was on display in the Empire's appearances from Marc Spector: Moon Knight #19-23, Amazing Spider-Man #353-358, and their appearances in Dead Man's Hand from Nomad Vol 2, Daredevil, and Punisher War Journal.

Thinking about it, I think they were actually the Council of Ten, but Number One died in MSMK, leading the remaining Council of Ten Minus One (i.e., Nine) to vie for power and the top rank in ASM #353-358.

3) Hydra was the first threat to SHIELD in Strange Tales #135-141, supposedly ended when the Imperial Hydra was killed. Over the next few months in Strange Tales, Tales of Suspense (Captain America stories) and Tales to Astonish (Hulk stories), various heroes fought the Secret Empire, AIM, Mentallo and the Fixer, all answering to a mysterious THEM. In Strange Tales #149, SHIELD pieced together the clues and realized THEM was Hydra, still active under the Supreme Hydra (Strucker), and were behind all these various threats.