It felt like we were watching the end of an era at the Santiago Bernabeu on Wednesday night as a once-mighty Manchester City were completely outplayed by Real Madrid in the shockingly one-sided second leg of their Champions League play-off – and Pep Guardiola concurred.

“Nothing is eternal,” the Catalan coach acknowledged after his team’s 6-3 aggregate defeat. “We have been extraordinarily extraordinary in the past, but not anymore.” Indeed, City are no longer one of the dominant forces in football – and what’s shocking about their decline is how sudden it has been. They’ve gone from a fourth consecutive Premier League title to fighting for fourth place in less than a year.

However, if history has taught us anything it’s that all great reigns must come to an end. Sometimes, it’s a long, painfully protracted process; on other occasions, it seems to happen almost overnight. But there’s always a moment, a match, a move or a managerial change that signals the loss of something that can never be replaced. Below, GOAL runs through some of the most dramatic falls from grace in football…