Learn German: Früher gab es einen König. - In the past, there was a king.

In German, the fixed phrase es gibt literally translates to "it gives", but it actually means "there is" or "there are". Since this sentence is in the simple past tense, es gibt becomes es gab, meaning "there was" or "there were".

Why is the word order gab es instead of es gab?

German follows the verb-second rule. Because the sentence starts with the time word Früher in the first position, the verb gab must come exactly second. The subject es is pushed to the third position, right after the verb.

Why does it say einen König instead of ein König?

The phrase es gibt (and its past tense es gab) always requires the noun that follows it to take the accusative case (the direct object case). Because König is a masculine noun, the word for "a" changes from ein to einen.

Doesn't früher mean "earlier"? Why is it translated as "in the past"?

While früher is the comparative form of früh (early) and can literally mean "earlier", it is very commonly used as a standalone word to mean "in the past", "formerly", or "back in the day".