LitCharts assigns a color and icon to each theme in Richard III, which you can use to track the themes throughout the work.
Power
The Throne and the State
Language
Women
Time
Summary
Analysis
At Salisbury, the Sheriff and a Guard lead a repentant Buckingham to execution. His request to speak with Richard is denied. He calls on the souls of Richard's other victims to get revenge on him by laughing at his execution. The day is All-Souls' Day and Buckingham declares it is fitting, considering all of the souls of Richard's victims. Buckingham wishes he had repented for his sins during King Edward's reign when he wronged the princes and Elizabeth's relatives and when he placed so much faith in the false Richard. Queen Margaret's curse, he reflects, has come true. He goes willingly to death, feeling his own wrongs are fairly punished by execution.
Though, as Richard's right-hand man, Buckingham committed brutal crimes and sins, he expresses repentance as he faces death, and regrets not having turned penitent sooner. He, too, like Hastings', Rivers, Gray, Vaughan, Elizabeth, and the Duchess, regrets having taken Margaret's curses so lightly now that her curse against him has come true.