To Anyone Who Knows About Welsh History

I’m Welsh entirely, but am living in England. I feel like I should know more about our history than I do, because the idea that has been put into my head is that we fought naked with aggressive tactics and were easy to defeat by some of my history teachers. Even though I’m about to head to uni with the Napoleonic Wars in mind, I would really like to know more about the history of my country. If anyone knows anything, I’d appreciate a comment. I’m not bothered by time period or what it contains, just as long as it’s About Welsh history.