One favorite family myth on my father's side is that El Sakakra, the village where they are from, has a lot of people who are descendants of Omar ibn al-Khattab عمر بن الخطاب who was the second Caliph after the prophet.

Al-Maqrizi's المقريزي in Al-Bayan wa Al-I'rab الببان و الاعراب  quotes one nassabah (genealogy expert) saying:

وأما العُمَريّون الذين بأرض مصر فإنهم ينسبون إلى عبد الله بن عمر بن الخطاب رضى الله تعالى عنه. وقال الشريف محمد بن أسعد الجواني النسابة: وهم يكذبون في ذلك لأن أنسابهم لاتتصل به وقد لقيت منهم جماعة وعرفتهم كذبهم بطريق علمته.

Here is a simplified Family Tree. It is missing several branches, for example siblings of Mohamed Baheyeldin, and their descendants.

Perhaps when I get a proper genealogy software, I will include more people.

All the present Baheyeldins are direct descendants (sons, grandsons, and granddaughters) of Mohamed Baheyeldin.

Mohamed Baheyeldin was the eldest son of Ahmed Mohamed Abdallah Mohamed Ali (El Gada') El Hosseini Omran, in Arabic: محمد بهى الدين احمد محمد عبدالله محمد على الجدع الحصيني عمران. The Hosseini name is spelled الحسينى or الحصين.

Here is a simple family tree.

Baheyeldin's Father

Ahmed was born in 1910 in El Sakakra, and was a teacher, then a school principal, then education inspector.

Mohamed Baheyeldin was born in 1931, in the village of El Sakakrah, north east of Hehia, in the governorate of El Sharkeyya in Egypt.

El Sakakra السكاكرة is a village about 3 kilometers north east of Hehia ههيا (also Hehya), which is the center (Markaz) to which Shersheima belongs. Hehia is about 15 kilometers north east of El Zaqaziq الزقازيق , the capital of the governorate of El Sharqeyya (Sharkeya or Sharkeyya الشرقية).

In the 1960s, it had only 2,100 people, and by the early 21st century, it has 6,000 to 7,000 people. 

Shersheima شرشيمة (or Shershema) is a twin village of El Sakakra, with a drainage canal separating them, which has been filled now.

My maternal granfather is Youssef Mohamed Abou Youssef.

Ancestry

The Abou Youssef Family are originally from North West Africa (Morocco? مغاربة), but settled in Alexandria, Egypt centuries ago. The name Abou in the family name was used by families of Moroccoan origin (e.g. Abou Hussein, ...etc.).

This particular branch of Abou Youssef were from Moharram Bey محرم بك district in Alexandria. Other Abou Youssefs lived in the Anfoushi الأنفوشي district of Alexandria. There is an apocryphal story in the family claiming that they are from a village called Dayrout ديروط near Rosetta رشيد.