Hello. There is no quick and easy way I know of that gets your wiki popular overnight. This may be especially true to a wiki about historical events, which the Wikipedia would likely cover moreso.
There are three suggestions I know of that can help:
Read Help:SEO and research how Google works, from how it looks at pages to the rules it uses to determine quality websites. The better the score, the higher your rank in searches.
Read Help:Best Practices and its blog posts, as they provide in-depth advice to how your wiki articles, nagivation bar, etc. should be to improve quality and SEO.
Introduce something unique to the wiki and keep building. As I mentioned, the Wikipedia is prolific with historical events, so your wiki will look like duplicate content. By introducing something unique, your wiki will likely be recognized as original, which boosts search rankings and thus more attention from users.
Regardless, the element of luck is the most influential, and your wiki becoming popular will require patience and creativity. As the "founder", you build the "foundation." I wish you the best!
A good main page is one of the best ways to attract clicks and increase your SEO. Your main page already looks better than most new wikis, so good job so far.
Here are some quick tips for how to make a good main page (I used this in a different similar thread):
Use correct spelling and grammar.
Have a good summary about what the wiki is about on the main page. Your topic seems very broad, so you may want to give some more specific focus to what you plan to cover...
Don't leave out key info:
If the wiki is fan fic, it should say so.Not really relevant in your case...
If the wiki is encyclopedic info it should say so. Looks like you already did this, so good.
If the wiki more like a personal sandbox, it should say so.Not really relevant in your case...
A nice header graphic related to the topic should show up near the top of the main page.
Put links to important pages on the main page.
Don't have pages that don't have any links to them from other pages.
Make or find nice graphics for main characters or objects (planes, ships, tanks, etc.) and put them with links on the main page. For you wiki, you could feature recently relevant historical figures or events...
This is sometimes called a profile table. You will see them on most good wikis.
If you have enough pages you can make a table with links to subtopics like characters, episodes, items, quests, etc.
Fandyllic's advice is solid. I would add a good looking and readable color pallet is another must. The transparent background makes it harder to read text, so I'd go with a solid one. Since your topic is more encyclopedic than sandboxy, I'd get rid of the squidward artwork on the main page, it doesn't really make the site look like a serious source but more of a joke site.
I would also look into learning HTML and CSS to help refine the look of the site. It's a trend in newer wikis, typically managed by younger people I've noticed, to go overboard with CSS and over design the wiki to the point where it's nearly unreadable with lots of effects and scripts, so I'd avoid that. As the old saying goes, keep it simple, stupid. But still, theirs lots of roughness on the main page that needs ironing out.
The header navigation is also really rough and hard to navigate with. Refine that and it'll make your site easier to use and more professional looking - which is key in a wiki like yours. For example, when you hover over a button, they still say "category" in it and have underscores.
But aside from all that, the most important step is to have quality content. If you use all the SEO tricks in the book but have lackluster content, you might get some traffic, but your site isn't going to be taken seriously, at least in the academic circle (lord knows crappy history sources have been all the rage lately). Look for relatable sources, don't fall for baloney sources like pseudohistory documents and for the love of god, don't rely on videos or documentaries. Cite actual peer reviewed works and primary and secondary sources. Don't be afraid to ask around on history forums like AskHistorians for help regarding a specific subject matter and always check the sources you're given.
Specialized coverage into specific events not really covered by other sites will likely help in SEO too. If theirs a specific period or event you're very much interested in, work on creating quality pages for that subject.
Lastly, lite advertisement can be useful in getting something off the ground. Don't spam it, rave about it, or annoy people with it, but link your sites content if relevant. Putting it in your profile description or signature on history forums and websites can also be a useful tool to give it more exposure without spamming.
But all that said, the unfortunate fact is theirs no guarantee your wiki will ever get big. Just work hard, always strive to improve it and expand it and you might find your audience eventually.