Where have all my old photos gone after iCloud sync?

[iMore Question]

After experiencing problems with my six-year old MacPro, I decided to switch to a new IMac. All my photos were stored on my IPhone 4S, so I though they were safe. However, I was unable to sync the photos with the new Photo app under el Capitan. No problem I thought, I'll upload them to ICloud and retrieve them from there. I duly switched on the "upload to ICloud" button. The photos were then deleted fro the iPhone (as expected) but did not then appear in ICloud, so they have now all disappeared!

Where have they gone? How can I retrieve them? There is about 180 GB of free storage in my iCloud, so lack of storage space is not the problem.

 

[Ledsteplin]

Did you have a back up in iCloud? They may be in a back up.
I always put my photos in more than one place. I use iCloud back up. Box and Dropbox. And they're in Google Photos.