On Wednesday, Deputy Attorney General Rod Rosenstein announced he had appointed former FBI Director Robert Mueller III to oversee the bureau's investigation into "Russian government efforts to influence the 2016 presidential election and related matters."

Here's a look at Robert Mueller's life and career:

Born August 7, 1944 in New York City

Graduated from Princeton University in 1966 and received a master's degree in international relations from New York University the following year

Served as a Marine Corps officer in Vietnam for three years, receiving a Bronze Star and Purple Heart, among other medals

Graduated from the University of Virginia School of Law in 1973

Worked for 12 years (1976-1988) as an investigator and prosecutor for U.S. Attorney offices in Northern California and Boston

Joined the Justice Department in 1989 as an assistant to then-Attorney General Richard Thornburgh. During his three-year tenure leading the DOJ's criminal division, Mueller oversaw the prosecutions of Panamanian dictator Manuel Noriega and crime boss John Gotti, as well as the investigation into the bombing of Pan Am Flight 103.

After two years as a partner at the Boston law firm of Hale and Dorr, Mueller rejoined public service in 1995 and went on to work for the U.S. Attorney's offices in Washington D.C. and Northern California.

Was nominated to be FBI Director by President George W. Bush on July 5, 2001 and officially assumed that position on Sept. 4. During his tenure, Mueller helped turn the FBI from a criminal investigative bureau into a counterterrorism and counterintelligence unit.

In 2004, Mueller, along with then-Deputy Attorney General James Comey, threatened to resign over the Bush administration's program of warrantless surveillance. Bush ultimately agreed to changes in the program and both men stayed on.

Mueller left the FBI on Sept. 4, 2013, having served two years beyond his ten-year term at the request of President Barack Obama. He is the second longest-serving FBI director in the bureau's history, behind only J. Edgar Hoover. Since leaving the FBI, Mueller has been a partner at the Washington D.C. law firm WilmerHale. He was expected to resign from the firm after being appointed special counsel to the FBI's Russia investigation.

Fox News' Catherine Herridge contributed to this report.

