Arms of Sigismund of Luxembourg


King of Hungary and Croatia, 1387-1487, King of Bohemia, 1419-1487, Holy Roman Emperor, 1433-1437 (1368-1437)

Blazon: Per pale barry of eight gules and argent (Hungary ancien) and gules a lion double-queued rampant argent, armed, langued, and crowned or (Bohemia moderne)

No one was admitted to the lists, who could not prove himself, at least maternally, to be one of four descents and display a legitimate coat armour.

-From Inquiries into the Origin and Process of the Science of Heraldry in England by James Dalloway, p90

Essentially, in order to compete in a tournament, you had to have at least one great-great-grandfather, if not more, who was noble and bore arms.