I have a gap in my photo library from 2006 to 2011 with only one photo per month. Where did my photos for those years go?

You may also want to check the dates of your photos. If your photos from before 2011 have been scans or saved photos, and the capture dates and locations may be wrong. Look, if you are finding some older photos among the photos from newer years.

Another possibility is, that the older photos may be in a format, that cannot be uploaded to iCloud.

• If you are finding the older photos on your Mac, check, if you are having an album "Unable to upload" in the sidebar of Photos. If not, create a smart album with the rule "Photo is unable to upload". Is this smart album empty?
• Is Photos on your Mac still showing "Uploading ... " in the status bar below "All Photos"?
• Are there any image files in a format different from JPEGs in your Photos Library?
• If you can find an older photo from before 2011, that is not on your iPhone, what is the file format?

It's really difficult to guess without knowing exactly how you were storing your images back then. When did you first notice these images were missing. When was the last time you are cretain they were not missing? I think the main question is do you have any old backups anywhere that might contain these older images.

Also - what version of MacOS are you running?

Some possibilities:

You have (or had in the past) more than one library with your images split accross them. Or at some point (2011) you migrated to a new machine and started with a new library. Do you have any older libraries somewhere. (I keep two libraries - one only for recent files and one on an external drive for all my images)

Or - you have in the past been using iCloud photos with optimise mac storage selected - so that the master images were not kept in your local library, and just migrated that library a new machine or OS version and stopped using iCloud.

Or - At some point you deleted older images from your mac thinking they would be kept in iCloud - not realising that they are also deleted from iCloud.

Or - You store your library in an external drive with an incompatible format (EG you have not formatted the drive to APFS or MacOS extended (journalled) - and this has resulted in damage to your library.

Or you have had a failing hard drive in the past which has caused loss of images.

Do any of these sound likely?

Hi

Are you looking in the all photos view?