<bdi><a href="https://en.wikipedia.org/wiki/en:Caspar_David_Friedrich" class="extiw" title="w:en:Caspar David Friedrich"><span title="German painter">Caspar David Friedrich</span></a>
</bdi>
circa 1825-1826
<a rel="nofollow" class="external text" href="http://www.sothebys.com/content/sothebys/de/auctions/ecatalogue/2014/impressionist-modern-art-day-sale-l14004/lot.155.html">Sotheby's, London (not for sale, only as a reference)</a>