  The colours of high redshift Type II QSOs are synthesized from observations
of moderate redshift systems. It is shown that Type II QSOs are comparable to
starbursts in their success at matching the colours of z_850-dropouts and
i_775-drops in the Hubble Ultra Deep Field, and more naturally account for the
bluest objects detected. Type II QSOs may also account for some of the
i_775-drops detected in the GOODS fields. It is shown that by combining imaging
data from the Hubble Space Telescope and the James Webb Space Telescope, it
will be possible to clearly separate Type II QSOs from Type I QSOs and
starbursts based on their colours. Similarly, it is shown that the UKIDSS ZYJ
filters may be used to discriminate high redshift Type II QSOs from other
objects. If Type II QSOs are prevalent at high redshifts, then AGN may be major
contributors to the re-ionization of the Intergalactic Medium.
