Embed YouTube HTML5 Video

I've got a modern web-application which doesn't work beyond IE 9 so I'm looking for a better way to embed the HTML5 version of YouTube-videos than using the iframe-code.

I tried the new <embed>-element but it keeps bringing up the Flash-player even in my Chrome 42 so what's the best way to embed my YouTube (and Vimeo) videos in my homepage?

I don't want to add another JS-library.