Lots of info on this on the net. Read forum on www.theforce.net and www.fanforum.comglennyong said:i was wondering.. the Sith law said that there can onli be one master and one apprentice at one time.
in epi 1... there was a darth lord who instructed Darth Maul to carry out the attack..
this dark lord i supposed it is Darth Tyrannus ? how come he didnt appear anymore....
And another point, how did Sidious have access to Sith powers ? by right he muzt have learnt it somewhere from another Darth Lord.. who was it ??
Darth Maul's master is Darth Sidious aka Chancellor Palpy

Darth Sidious was thought to be the apprentice to Darth Plageous (the wise) and was the one who killed him