Etymology of “that” as both pronoun and conjunction

“That” can be used both as a pronoun and as a conjunction. For example,

I know that it is raining.

Give me that.

This is unique to English as far as I know. In French and Spanish, for example, the two uses of “that” are distinct (c.f. “que” vs. “ça”). Looking online, this is true for non-romance languages as well.

Is there evidence that English originally had two words for “that”, depending on its context, but the words eventually merged? Wiktionary suggests such a merger would have occurred before the development of Old English.