Sebastian has a younger brother named Fabian
Yes, he is Guy's younger brother.
Sebastian
Sebastian is Viola's brother. They strongly resemble each other.
Jamal Thomas
Viola and Sebastian's father was also called Sebastian. See Viola's line in Act 5 "Of Messaline. Sebastian was my father. Such a Sebastian was my brother too."
Johan Sebastian Bach was raised by an older brother, saw it in "who wants to be a millionaire".
Yes, Edward is the eldest brother of the trio. The ages from oldest to youngest are as follows: Edward, Dominic and Sebastian. I know he's his brother because my friend knows Sebastian. Hope that's helped!
He has a younger brother named Sebastian.
He is actually Jonathan, Clary's real brother.
Yes, Clary from the "Mortal Instruments" series by Cassandra Clare has a brother named Jonathan (also known as Sebastian Verlac or Sebastian Morgenstern). He plays a significant role in the series as a complex and dark character.
No, John Cabot was the father of Sebastian Cabot.
There is no written record of any siblings that Sebastian may have had.