HELP! How can I back up two phones pictures to iCloud to set up my new iphone6?!

i have just got a new iPhone 6.

had an iPhone 5 after damaging it I managed to backit up to iCloud and started using an iPhone 5c. When I restored the iPhone 5c to have everything from my iPhone 5 everything transferred apart from the pictures. I have used the iPhone 5c for 6 months and now have the iPhone 6.

i Want all of the pictures from my original iPhone 5 and my 5c to be transferred to my iPhone 6 but can't figure out how to update and back up ALL pictures to the cloud so I can restore my iPhone 6 with all pictures and settings.

SO far I can restore from the back up of either the 5 OR THE 5c but NOT BOTH.

any help would be much appreciated !

THanks