terminated. Feedback from AGN (e.g. Silk & Rees 1998; Hopkins et al. 2005) or starburst-driven superwinds (e.g. Diamond-Stanic et al. 2012) are leading contenders for rapidly quenching distant galaxies, while jet-mode AGN feedback may be required to maintain the “red and dead” phase (e.g. Best et al. 2006).

In addition to the quenching of star formation, massive galaxies must also undergo a dramatic structural transformation, to produce the spheroid-dominated population we see today. The transition appears to occur at $z>1$ for most galaxies with M$_{\ast}>
10^{10.5} ~$M$_{\sun}$ (Mortlock et al. 2013; Bruce et al. 2014), but it is unclear if quenching and structural transformation occurred during the same event. Over the last 10 years it has also emerged that quiescent galaxies were significantly more compact in the early Universe compared to the present day (e.g. Daddi et al. 2005; Trujillo et al. 2006; van Dokkum et al. 2008; Belli et al. 2014). Plausible explanations for the dramatic size growth include minor mergers (e.g. Bezanson et al. 2009; Naab, Johansson & Ostriker 2009) or expansion due to mass loss (Fan et al. 2008). For the population of quiescent galaxies as a whole, however, there may also be an element of progenitor 