"Lost glory" refers to a situation where something or someone used to be great, respected, or successful, but no longer holds that status or importance.
Otherwise, he shld willingly step aside for someone else who is willing and ready to bring back d lost glory of d club. (justarsenal.com)
The SUN reports that Man U have spent 600 million in 4 years to try to regain lost glory all to no avail. (justarsenal.com)
Having outlasted their spans of legitimate productivity, they attempt to recapture long lost glory — only to write an ignominious final chapter to their careers. (educationworld.com)