The phrase "were relevant to" indicates a connection or importance to a certain subject or topic. Synonyms for this phrase may include "pertained to," "related to," "connected to," "associated with," "had bearing on," "had relevance to," "applied to," "impacted," "influenced," or "had significance for." These synonyms communicate the same meaning as "were relevant to" and can be used interchangeably in various contexts. Whether discussing a specific event, historical period, or scientific theory, using one of these synonyms can help to clarify and strengthen the overall message by emphasizing the relevance and importance of the subject at hand.