Recover deleted messages

The short answer is you probably can't. If you're using iCloud Syncing for Messages, they are not part of any back up so, once deleted, they are gone. To determine if you are using iCloud Syncing, go to Settings, tap on your account at the top of the screen, tap on iCloud and check to see if "Messages" is enabled. If it is, you're out of luck.

If you are not and you have a back up that contains the messages, you can try restoring your phone from that back up:

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Note that restoring your phone from the back up will overwrite everything currently on the phone.

Please also note that the thread linked to by lafeef above is out of date (sorry, lafeef!)

Hey there,

See this discussion ☞ My phone deleted my text messages by mist… - Apple Community