There are fans who believe that Roberts Rebellion wasnt simply started by the abduction of Lyanna Stark by Crown Prince Rhaegar Targaryen instead there was an element of empire building instigated by the likes of Rickard Stark (Neds father) along with the Tullys and the Arryns. The Mad King has often been called paranoid for believing that there was a faction out there to get him and in fact he was right. Robert Baratheons father died young and so the young Lord was sent to foster with Jon Arryn alongside Ned Stark. They hadnt planned for the events that would ultimately result in the rebellion after Lyanna was taken as when her oldest brother arrived at Kings Landing and demanded combat with Rhaegar, the King threw him and his men into prison. Then when their fathers arrived to demand their release, he had them all killed. Rickard demanded trial by combat and as his champion, Aerys II chose fire setting Lord Stark alight while encased in a full suit of armour. But the theory states that it wasnt simply the Lords of the great houses that were the power behind the play that ultimately resulted in the Rebellion it was actually the Maesters working together. This couldnt have gone undetected by the Grand Maester, so in order for this theory to be correct then Pycelle must have been behind the whole thing.