  The propagation of UHECR nuclei for A=1 (protons) to A=56 (iron) from
cosmological sources through extragalactic space is discussed in the first
lecture. This is followed in the second and third lectures by a consideration
of the generation and propagation of secondary particles produced via the UHECR
loss interactions. In the second lecture we focus on the generation of the
diffuse cosmogenic UHE-neutrino flux. In the third lecture we investigate the
arriving flux of UHE-photon flux at Earth. In the final lecture the results of
the previous lectures are put together in order to provide new insights into
UHECR sources. The first of these providing a means with which to investigate
the local population of UHECR sources through the measurement of the UHECR
spectrum and their photon fraction at Earth. The second of these providing
contraints on the UHECR source radiation fields through the possible
observation at Earth of UHECR nuclei.
