Defer loading of images without the use of JS

I want to defer the loading of images in an HTML file until after all other assets have loaded or for a set amount of time. I would like to do this without JS.

I already use a deferred image loading technique that uses JS in our web app. However, a version of this app runs without JS and I'd like to have the same functionality if possible. I posted this in the hopes there may be some little known HTML5 attribute I can use for this. Any workaround are welcome.

Load priotity

If possible, it would be good to break up the image loading into blocks. I'm ok even if it's all just one block as well.

1. All HTML / CSS
2. Image block
3. Image block

Note : I've already looked into having lazy loading only for the JS app and having the image load right away for my pure HTML version (as described here), that's my fallback.