Because of confusion, I have two or three catalogues. I want to combine them

[johnm is lost]

I have accidentally been switching between catalogues and have lost track of everything. I would like to have ONE catalogue combining two or three catalogues. Is there a way to start an entirely new Catalogue, combine the older catalogues into this new catalogue AND avoid having duplicates. The two or three catalogues have approximately 22000 photos each - both are named Lightroom 4, Cat 2-2-3 Lightroom Classic and Lightroom 4 Cat 2223 Lightroom Classic.

[John Waller]

Moved from Downloading, Installing, Setting Up forum.

[Rob_Cullen]

You will find four articles on "Merging Catalogs"  Stages 1,2,3,4  at-

https://www.lightroomqueen.com/lightroom/catalogs/

I suggest you read each one carefully.