Cairo was also home to an Ashkenazi community, which was founded in the aftermath of the progroms that hit Europe in the latter part of the 19th century. The Ashkenazi community had its own Synagogue where they would hold services according to their customs and traditions. Still the basic community services (cemetery, sheḥita, education) were provided by the Sephardic community for both. In 1893 the lay leaders of the Ashkenazi community decided to have their own services. Rabbi ben Shimon (1847-1928) did not refuse and the Sephardic community gave the Ashkenazi community a parcel in the cemetery for free. They also appointed their own Rabbi, Rabbi Rafael Ginzburg, who passed away three years after his appointment. At the end of the 19th century he was succeeded by Rabbi Aharon Mendel haCohen, a great rabbinical scholar from Tiberia. Rabbi ben Shimon and rabbi Mendel worked together for the benefit of the Jewish community. Rabbi Ben Shimon brought Rabbi Mendel as part of his Bet Din (rabbinical court). Even though Rabbi Ben Shimon in his position as the Chief rabbi of Egypt, appointed in 1893 by the Turkish Sultan, was technically the single authority of the entire Jewish community, before he issued a new rule, he would consult with rabbi Mendel and seek his approval. The relationship and camaraderie between the two Rabbis was known as an example of team-work and mutual respect between a Sephardic and an Ashkenazi rabbi.
Even when they would disagree on certain issues, they would still respect each other greatly. In 1903, rabbi Mendel together with rabbi Zvi Makowsky (va-ashiba shofetaikh) planned to reestablish the Sanhedrin (ḥiddush hasemikha), i.e., a universal Rabbinical Supreme Court that, among other things, would (i) resolve all the disagreements between Rabbis and arrive at one final Halakhic decision, mandatory for all (ii) appoint community rabbis who will act on behalf of this Sanhedrin. Rabbi Ben Shimon was very enthusiastic about the idea in general, but he was skeptic about its realization. In a beautiful letter addressed to rabbi Mendel (which could be found in nehar miṣrayim B, pp. 583-587) he tried to dissuade him. Rabbi ben Shimon's opposition to this idea was based purely on pragmatic grounds: In present times --he said-- with so many divisions among the Jews, it will be impossible to persuade all the Rabbinical and lay leaders to surrender their local authority and empower one single entity above them. Unfortunately, Rabbi ben Shimon was right and the project never came to fruition.
Read more HERE about past and present attempts to renew the Sanhedrin