<div class='container'>
    <div class='background'><img src='/img/url/here.jpg' /></div>
    <div class='foreground'>Overlay copy</div>
</div>

.container {
    position: relative; /* this is required to keep all absolutely positioned child elements contained */
    overflow: hidden;
    height: 100px;
    width: 1200px;
}

.background {
    position: absolute;
    left: -200px;
    top: 0;
    height: 100px;
    width: 1200px;
    z-index: 1;
}

.foreground {
    position: absolute;
    left: 50px;
    top: 50px;
    height: 50px;
    width: 300px;
    z-index: 2;
}