The Long Ships (1964) on Netflix

A Viking thane (nobleman) and master-shipbuilder's adventurous son Rolfe returns after years of adventurous plundering, claiming he's on the trace of the legendary golden bell. After king Harald of Nordland pays the latest ship, ordered in advance for the royal funeral, pittance by deducting due tribute, the thane is amused his son has already pressed his younger bothers and a whole crew aboard for his treasure hunt, and assured safe passage by kidnapping the royal princess. They reach the Moorish tyrant Aly Mansur's Barbary Coast domain, but are overpowered and enslaved by his massive army. Torture and death threats lead to an uneasy alliance on the gold quest, basically a truce until the final confrontation at their return.