<!DOCTYPE html>
<html>
<head>
<style>
img {
position: absolute;
left: 0px;
top: 0px;
z-index: -1;
}
</style>
</head>
<body>
<h1>This is a heading</h1>
<img src="w3css.gif" width="100" height="140">
<p>Because the image has a z-index of -1, it will be placed behind the text.</p>
</body>
</html>