His team won the 2006 Quidditch World Cup final. Sankara was so popular after the tournament that he was elected as Burkina Faso’s Minister for Magic. After a few days he resigned the post, in favour of continuing with his Quidditch career (Pm).
Joshua is a biblical name meaning "god is salvation" (QuickBabyNames: Joshua).
His surname may refer to Thomas Sankara (1949-1987), who was President of Burkina Faso from 1983-1987 and a "charismatic and iconic figure of revolution" (Wikipedia: Thomas Sankara).