Very little is known about Palpatine during his Birth Years and Youth, the most important knowledge garnered was that Palpatine at some time during his youth was apprenticed to Darth Plagueis the Wise and came to understand the powers of the Darkside, before however his training was complete however Sidious feared that his Master would replace him and so killed Plagueis - adopting all the Relics and Holocrons left behind after his Master's Death.