Today's web resource, a long-established one good for all sorts of historical and up-to-date uses, is the Perry-Castañeda Library Map Collection at the University of Texas at Austin. This should be one of your first stops for maps or links to maps concerning any recent event, or for historical topics, like the Peace of Westphalia of 1648 (end of the 30 Years War).
Another resource at UT I just discovered is a huge collection of historical portraits. This will be one of my first stops any time I'm putting together an illustrated lecture. It has its limits, though. All the pictures I've looked at -- a couple of dozen -- are in black and white. If the original portrait was a sketch or a black and white photo, that's OK, but today's audience -- including me -- wants color if it's available.
Another limit is the fact that many of the pictures are imaginative depictions of people we have no visual record of. Included with this post are UT pictures of Alfred the Great, 9th century kind of Wessex, and Aspasia, famous courtesan of Periclean Athens. There may be some ancient busts that have been identified as Aspasia, but one has to wonder about their authenticity, and even if you accept them as real, this sketch is really a fantasy based on who-knows-what. Alfred's even a worse case. The picture is purely generic. Some 19th-century artist has created a "portrait" based on 14th-century and later pictures of some great king or other.
In other words, I'm not sure either the picture of Aspasia or the picture of Alfred gets you any closer to those people. They may even be a barrier to understanding them.
But if you need a quick pic of Midhat Pasha, the 19th-century Ottoman reformer, you can look at UT, if you are too lazy to look at Google Images.
One big advantage of the UT Portrait Gallery: It cites its sources!