  Chandra has performed a 1.4 Ms survey centred on the Hubble Deep Field-North
(HDF-N), probing the X-ray Universe 55-550 times deeper than was possible with
pre-Chandra missions. We describe the detected point and extended X-ray sources
and discuss their overall multiwavelength (optical, infrared, submillimeter,
and radio) properties. Special attention is paid to the HDF-N X-ray sources,
luminous infrared starburst galaxies, optically faint X-ray sources, and
high-to-extreme redshift AGN. We also describe how stacking analyses have been
used to probe the average X-ray emission properties of normal and starburst
galaxies at cosmologically interesting distances. Finally, we discuss plans to
extend the survey and argue that a 5-10 Ms Chandra survey would lay key
groundwork for future missions such as XEUS and Generation-X.

Astrophysics