There are numerous synonyms for the phrase "were part of" that can be used to add variety and richness to your writing. Some of these synonyms include "were members of", "were constituents of", "were components of", "were elements of", "were sections of", "were pieces of", "were aspects of", and "were portions of". Each of these synonyms can convey a slightly different nuance or tone, so it's important to choose the one that best fits the specific context of your sentence. Experiment with these and other synonyms to add depth and precision to your writing and make it more engaging for your readers.