Wikipedia, which comes in handy when you can't find source materials (I especially use it for world history, though the foreign language versions rather than the Japanese one)

For those of us living in rural areas without many large bookstores nearby, online encyclopedias and dictionaries are incredibly helpful.

In the first place, if the person or event you want to research is obscure, you might not even know which documents to look at to begin with.

Therefore, searching online is a convenient way to get a "foothold" in such cases.

However, online information is a mixed bag, and there are also "fakes" and "misunderstandings."

That is why I make sure to choose well-known (reliable) sites to use as "source material," and ones where the information sources (such as bibliographies) are clearly stated.

I often use "Kotobank" and "Wikipedia," but...

Wikipedia is especially convenient when researching foreign history or figures.

This is because even if there isn't detailed information or even an entry in the Japanese version, it is often included if you look at the foreign language version.

(Depending on the entry, the Japanese version is sometimes a complete "translation" of the English version, with the same content.)

To view a foreign language version, select a language other than Japanese in the "Language" menu.

Surely, the French version would be the most detailed for French history, and the Spanish version for Spanish history, but...

I don't know French or Spanish (my second language in college was Chinese—incidentally, because I wanted to read classical Chinese in its original pronunciation), so I can only choose the English version...

In any case, a foreign language is still a foreign language, so you do have to take on the challenge of "reading and understanding" it.

Modern browsers usually come with translation features, but...

Honestly, historical English texts are often too technical, and the translations can end up being a mess.

Personally, I think it's faster to only look up words or sentence structures I don't understand partially on Google rather than translating the whole text at once.

Even if you feel you're too bad at English to manage, you can still understand portraits and birth/death dates, so I don't think it's a waste of time to look at them...

(In particular, "birth and death dates" can sometimes be wrong depending on the source, so it's useful for "cross-checking," and it also serves as material to determine family relationships, such as whether a "brother" is an older or younger brother.)

In my case, I rely on Wikipedia almost every time for my historical short story series "Ren'ai Gunzo Historica," which is based on the "romances of real princesses in Western history."

(Sometimes, after researching on Wikipedia, I even purchase the "references" listed there.)

In particular, when I wrote the short story "Marguerite de Navarre" about the French king's sister, queen of a small nation, and also a bestselling romance (erotic) author of the time, titled "The Sweet Fan Fiction of a Literary Queen"...

Queen Marguerite was such an "obscure" figure that there was almost no source material available, so I was greatly helped by the English version of Wikipedia.

I struggled with reading the English, but...

It was actually fun to be able to learn a lot of "niche English" that you wouldn't really come across in a standard English conversation class or textbook.

(Words like "mistress" or "half-sister" don't exactly appear in textbooks, do they...?)

By the way, I have already compiled some English words related to "aristocratic society" on the site's "Fantasy English Dictionary" page...↓

I hope to eventually compile and post the "slightly sordid (?) aristocratic society English" I picked up while researching materials for "Marguerite de Navarre" as well.

(I can only do it when I have a block of free time, so I don't know when that will be...)