HYDRA

HYDRA is a world-wide criminal organization dedicated to global domination, with the intended goal of establishing a "New World Order". Over the years, HYDRA secretly infiltrated S.H.I.E.L.D. and used the agency to their advantage in many ways. They recruited a large sum of all the agents and silently killed off anyone who got in their way.

Nazi HYDRA
Hydra was founded under the ideology that humanity should not be allowed to govern itself. Under the leadership of Johann Schmidt, it was an organization that created advanced technologies for Nazi Germany until Schmidt turned on other German forces in 1943. During World War II, it was opposed by the Allied Strategic Scientific Reserve. Starting in November 1943, Steve Rogers led many attacks on Hydra installations throughout Europe. In March 1945, Schmidt's base fell and Schmidt was apparently killed along with Steve Rogers.

The S.S.R. used both the fall of Schmidt and Nazi Germany to crush what was left of HYDRA, they arrested key members such as Werner Reinhardt and HYDRA's leading scientist Zola.

United States HYDRA
After World War II, the United States founded S.H.I.E.L.D. and recruited leading Nazi scientists including Arnim Zola, who restablished HYDRA as a covert organization within SHIELD. In its new form, HYDRA dedicated itself to securing mankind by guiding global events to manipulate people into willingly sacrificing privacy and freedom in exchange for security. To this end, HYDRA utilized the presumed-dead Bucky Barnes, whose memory they repeatedly erased and whose lost arm they replaced with a mechanical prosthesis, to assassinate figures such as Howard Stark. HYDRA's continued existence remained a secret until the late stages of Project Insight, which resulted in the collapse of United States governed S.H.I.E.L.D. in 2014.

Independent HYDRA
After the fall of S.H.I.E.L.D., Wolfgang von Strucker took major control what was left of HYDRA. Strucker who was working in Europe agreed with the other leaders of HYDRA that HYDRA's operations in the United States needed a leader of its own. He agreed to allow Daniel Whitehall, to lead HYDRA's affairs in America while Strucker continued building HYDRA strongholds in Europe.

Whitehall's reign in America was short lived and in late 2014 he was killed by S.H.I.E.L.D. Director Philip Coulson. Coulson then used his knowledge of HYDRA to attack the leading American HYDRA leaders before they could elect a new head of HYDRA in America. This has left HYDRA's interests in the United States vulnerable for 2015.