The answer
Nathanael is best known and recognized as St. Bartholomew the Apostle by most Christian scholars. He is mentioned twice in the Synaxarium—Coptic Lives of the Saints—(1) Thoout 1 and (2) Hathor 19, under the name of St. Bartholomew the Apostle. He preached Christianity in Al-Khargah Egypt, the land of the Berbers, and cities on the Mediterranean Coast. He converted many and taught the people to live in chastity. He was martyred by King Agrippa, who ordered that St. Bartholomew be placed in a sack full of sand and be thrown into the sea.References:
http://copticchurch.net/synaxarium/1_1.html#2
http://copticchurch.net/synaxarium/3_19.html#2
Answered by His Eminence Metropolitan Youssef (opens in a new tab)