From the Wikipedia page  which has a list of participants.
Buckingham's rebellion was a failed but significant uprising, or collection of uprisings, of late 1483 in England and parts of Wales against Richard III of England. To the extent that these local risings had a central coordination, the plot revolved around Henry Stafford, 2nd Duke of Buckingham, who had become disaffected from Richard, and had backing from the exiled Henry of Richmond (the future king Henry VII). Buckingham's precise motivation has been called "obscure"; he had been treated well by Richard. The traditional naming of the rebellion after him has been labelled a misnomer, with John Morton and Reginald Bray more plausible leaders.
Horrox has commented that where modern accounts of the chronology are based on the four Acts of attainder of early 1484, they should be treated with caution. Rebels took arms against the king, who had assumed power from Edward V in June of that year. They included many loyalists of Edward V, and others who had been Yorkist supporters of his father Edward IV.
Preparations, however, did not live up to the broad base of the rebellion: Richard in the field defeated the rising in a few weeks in autumn 1483. In those military terms it was a complete failure. It also, however, polarized opinion about Richard as king, and its effect over the next two years was to drive a number of leading figures into Richmond’s camp.