The Dark Energy Survey (DES) Collaboration has started a 5000 square degree imaging survey of the southern galactic cap using a new 3 sq. deg., 520 Megapixel CCD camera, the Dark Energy Camera (DECam), mounted on the Blanco 4-meter telescope at the Cerro-Tololo Inter-American Observatory in Chile. DECam has achieved first-light in September 2012. Commissioning and science verification were successfully finished in February 2013 and the survey proper started on August 31, 2013. DES data will be used to place new and tight constraints on the nature of dark energy via the history of the cosmic expansion rate and the growth of large-scale structure, using the four complementary techniques recommended by the Dark Energy Task Force: weak gravitational lensing, galaxy cluster counts, large-scale structure including baryon acoustic oscillations, and Type Ia supernovae. In this talk, the science projections and prospects will be described, together with the status of the project and the first results obtained from commissioning and science verification data.