The Prisoner of Zenda (1952)

Rudolph Rassendyll (Stewart Granger) is a British tourist visiting the nation of Ruritania in the Balkans. A number of people comment upon Rassendyll's remarkable resemblance to Prince Rudolph, who in a matter of days is to be crowned the nation's new king, and the prince's staff even arranges a meeting between the two men. But Rupert (James Mason), Rudolph's devious brother, believes it is he who should be the king, and he arranges for Prince Rudolph to be poisoned the night before his coronation. Desperate, Rudolph's minders beg Rassendyll to participate in the ceremony in Rudolph's place so that Rupert cannot take the throne. Rassendyll agrees, and the ceremony goes off without a hitch, but when Rupert's men discover this subterfuge, they imprison the real Prince as they threaten to reveal the secret of the new "king." Rassendyll's dilemma is compounded when he finds himself falling in love with Princess Flavia (Deborah Kerr), Rudolph's intended.