Wish you guys would stop calling him Palpatine, his real name is Sidious.Palpatine is just his alias after he joined with the Sith lords.
No. His name is Palpatine. He's a native from Naboo, and Palpatine is/was his surname. He decided at a young age to go only by his surname and not his given first name which to this day is still unknown. For example he could have been named John Palpatine, and decided to drop John.
After he joined with Darth Plagueis, and became his apprentice did he become Darth Sidious.