This research attempts to describe the identity development of students/teachers who used a virtual social network –Facebook to work with historical mathematics and mathematicians in the frame of a second degree course. Fifteen participants aged from 24 to 53 years old participated in the course in which they were required to attend mathematical Facebook sites involved with math history. The research findings arrived at using the grounded theory approach indicate that working with historical mathematicians and talking and discussing their work in virtual social networks, students/ teachers developed their identity in four aspects: (1) the educational aspect, (2) the cultural aspect, (3) the personality aspect, and (4) the ethnic aspect. These identity aspects were developed due to the different conditions of the learning environment, together with the actions/ interactions of the participants. Specifically, working with the history of mathematics in virtual social networks made the participants aware of (1) the advantages of integrating technology in learning and teaching, (2) the advantages of integrating history in the learning and teaching of mathematics and science, and (3) the possibility to move their culture to one that is involved more in science and mathematics. In addition, working with the history of mathematics in virtual social networks made the participants proud of their heritage and as a result they increased their self esteem.