New wide-field u'g'r'i'z' Dark Energy Camera observations centred on the nearby giant elliptical galaxy NGC 5128 covering ~21 deg^2^ are used to compile a new catalogue of ~3200 globular clusters (GCs). We report 2404 newly identified candidates, including the vast majority within ~140kpc of NGC 5128. We find evidence for a transition at a galactocentric radius of R_gc_~=55kpc from GCs 'intrinsic' to NGC 5128 to those likely to have been accreted from dwarf galaxies or that may transition to the intragroup medium of the Centaurus A galaxy group. We fit power-law surface number density profiles of the form {Sigma}N,R_gc{prop.to}R_gc_^{Gamma}^ and find that inside the transition radius, the red GCs are more centrally concentrated than the blue, with {Gamma}inner,red~=-1.78 and {Gamma}inner,blue~=-1.40, respectively. Outside this region both profiles flatten, more dramatically for the red GCs ({Gamma}outer,red~=-0.33) compared to the blue ({Gamma}outer,blue~= -0.61), although the former is more likely to suffer contamination by background sources. The median (g'-z')0=1.27mag colour of the inner red population is consistent with arising from the amalgamation of two giant galaxies each less luminous than present-day NGC 5128. Both inwards and outwards of the transition radius, we find the fraction of blue GCs to dominate over the red GCs, indicating a lively history of minor mergers. Assuming the blue GCs to originate primarily in dwarf galaxies, we model the population required to explain them, while remaining consistent with NGC 5128's present-day spheroid luminosity. We find that several dozen dwarfs of luminosities L_dw,V_~= 10^6-9.3^L_V,{sun}_, following a Schechter luminosity function with a faint-end slope of -1.50<={alpha}<=-1.25 is favoured, many of which may have already been disrupted in NGC 5128's tidal field.

Cone search capability for table J/MNRAS/469/3444/psc (Point and point-like sources photometry (tables 2 and 3))

Cone search capability for table J/MNRAS/469/3444/gc (Globular cluster candidates sources photometry (tables 4 and 5))