  In this article, I review past, current, and future advances on the study of
radio-loud AGN (RLAGN; radio-loud quasars and radio galaxies) lifecycles
exclusively in the remnant and restarting phases. I focus on their dynamics and
energetics as inferred from radio observations while discussing their radiative
lifetimes, population statistics, and trends in their physical characteristics.
I briefly summarize multi-wavelength observations, particularly X-rays, that
have enabled studies of the large-scale environments of RLAGN in order to
understand their role in feedback. Furthermore, I discuss analytic and
numerical simulations that predict key properties of remnant and restarting
sources as found in wide-area surveys, and discuss the prospects of future
surveys that may shed further light on these elusive subpopulations of RLAGN.
