Activation code

I'm the original owner I bought it for my nephew from the Apple Store it was 4 years ago and have no clue of what password was set up

Thanks Eric have also tried that but no idea of what the email address even was. He has since changed it and uses one he set up himself for iTunes on the iPad. On iCloud with those a details his iPad is not a device

Yes I have tried all the options with iCloud I have also tried to reset password on email account with every veriation of his name to see if we can get in that way to reset the iCloud password but no joy

Thanks Eric, I contacted Apple Support this morning and after speaking with a few different people they were able to locate my purchase invoice, this has now been forwarded to the activation lock department and they will remove it from the iPad. It will take about 5 working days but at least it will be working again. Thanks so much for all your help.