Synonyms for "old as history" could include "ancient," "timeless," "long-standing," and "historic." Other options might include "prehistoric," "antique," "vintage," or "archaic." Depending on the context, the phrase might also be translated as "hallowed," "legendary," "established," or "traditional." Essentially, any term that evokes a sense of deep, enduring history or age could be used instead of "old as history." In some cases, the phrase might be modified to better suit the specific context, such as "as ancient as the pyramids" or "as timeless as the stars." Ultimately, the most appropriate synonym will depend on the writer's intended meaning and tone.