Fade/Blend Two Images Together

1.Open the first image you want to fade

2.Go to Edit>Select All and then Edit>Copy

3.Open the second image

4.On the second image, switch to quick mask mode, the button on the bottom right with the mask icon.

5.Create a Linear Gradient Fill with the bucket tool, from White to Black, starting from one end of the picture to the other.

6.Now un-click the quick mask mode button.

7.Go to Edit>Paste into selection.