Arn Magnusson is born in Western Sweden in the year 1150. He becomes a skilled warrior, and meets the love of his life, Cecilia but they are forced them apart. Cecilia is imprisoned in a monastery. Arn is sent to the Holy Land as a Knight Templar, where a holy war is raging. Arn and Cecilia both have to struggle to survive, to learn how to confront evil and overcome physical hardship. Their separation causes their faith in God to waver - though not their faith in each other, and their conviction that they will one day be reunited. When Arn returns home, he has to fight for his love and what has become his mission: to unite Sweden into one Kingdom