Harald Hardrada: Viking Mercenary (Part 1)

Picked one by one from a mixed channel. Transcript check: both title readers certain; 3 of 5 sampled certain picks confirmed by transcript, none failed. Channel rule: Include long-form history documentaries and explainers with plain descriptive titles (e.g. 'The Bronze Age Collapse (1177 BC)', 'Battle of Grunwald 1410', 'The Entire History of the Inca Empire', 'Bad Eyesight Before Glasses: What Did People Do?'). Exclude any video whose title uses all-caps emphasis, withheld-information hooks, or pop-culture/celebrity tie-ins, and exclude interview episodes framed around celebrity rather than history.