On the usage of 'es' as a subject

Question

Hopefully I can explain this alright.

Take the following sentences, one in English and it's German translation.

In the 1800s, one of the early challenges was to explore the land and find suitable areas where people could settle.

Im 19. Jahrhundert war es eine der ersten Herausforderungen, das Land zu erkunden und geeignete Areale zu finden auf denen sich Leute niederlassen konnten.

I'm confused with why 'es' was used in the German. Perhaps I am over-analyzing this too much, but what exactly is the subject in the english version? I believe it to be the whole phrase 'One of the early challenges' or perhaps just 'One'. And in the German version 'Es' is the subject, correct?

But then that would make the german sentence's english equivalent seem moreso to me like this:

In the 19th century, it was one of the first challenges: to explore the land and to find suitable areas on which they the people could settle.

But are these 2 english sentences (the first one given and this new version) consisting of the same subject? No, right? You have 'it' as the subject in the second version. And it can easily be seen how 'es' would then be in the translation acting as the subject. My point being that I'm unsure on how to translate particular english sentences (like the first english version) into german because I'm unsure of how to present the subject in german.

My question I guess is how do you know when you need to use 'es' as the subject in german?

What grammatical rule was preventing me from omitting 'es' entirely in the german version?

Thanks

Answer 1

I think your translation "In the 19th century, it was ..." sums up what's going on in the German version; just leave out the colon, which doesn't seem necessary anyway. Grammatically, the es here is the "impersonal es" which is used as a subject when there is nothing around that's "doing" whatever it is the verb says is going on. It's almost always translated as "it" in English. The most basic use is for weather related statements:

Es regnet. -- "It's raining."

Both English and German have a collection of impersonal verbs, meaning verbs which require or take on a different meaning when used with the impersonal es/"it". But the two languages don't always agree on which verb ought to belong to the respective collections. For example ziehen -- "to be drafty" is an impersonal verb in German but you'd use an adjective for the same meaning in English:

Es zieht. -- "It's drafty."

But sein/"to be" is an impersonal verb in both languages and they use it in much the same way. Specifically, you'd use it to describe a fact, a general condition, etc. without naming what you're trying to describe. For example:

Heute ist es schön. -- "It's beautiful today. (It's a beautiful day.)"
Es ist nett, dass du mich besuchst. -- "It's nice of you to visit (me)."

In the second example, the es/"it" refers to the second clause, but both languages require it to serve as a placeholder in the main clause.

German is not as picky as English about every sentence including a subject, especially when leaving it out would not violate the V2 verb placement rule which German seems to regard as paramount. For example:

Mir ist heiß -- "(To) me (it) is hot." or "I'm hot."

But if the es is used as a placeholder then it seems to be required. Note that there is no other plausible subject in your example sentence; Im 19. Jahrhundert is a prepositional phrase serving as an adverb, the eine der ersten Herausforderungen is a predicate serving as the object of sein, and the rest is in subclauses. (I'm pretty sure that some commas are missing in the German version; German is more picky about that than English.) So while I'm sure the sentence could be rephrased to not use es as in the original English version, you can't just drop it without making any other change.