TV Guide National Geographic Channel Tuesday

The mid-10th-century reign of Harald Bluetooth marked the beginning of a second Viking age, but the Normans finally won the English Kingdom in 1066.

The mind of the Supreme Leader of North Korea, Kim Jong Un, is explored, as he tries to improve his dysfunctional kingdom.

The Supreme Leader of North Korea, Kim Jong Un, tries his hand at diplomacy by seeking legitimacy for his totalitarian regime.

An aspiring star makes use of drugs in an attempt to cope with building stress; a questionable doctor freely prescribes Adderall for weight loss.

A Detroit couple spends their days panhandling to support their crack habits; a Border Patrol agent searches a vehicle and finds bags of uncut cocaine.

Police activity made many illegal drugs scarce in Washington, D.C., but PCP was harder to eliminate, and its users are often subject to psychotic delusions.

Drug use in New York City is explored, with an emphasis on how Dominican Republic cocaine dealers have become big suppliers in the city; bonus content included.

Survivalist Hazen Audel fights through the rainforest in an epic survival challenge.

Hazen Audel faces open savannah in an extreme survival challenge.

Survivalist Hazen Audel tackles the highlands in an epic Amazon survival challenge.

Survivalist Hazen Audel faces soaring waterfalls in an epic Amazon survival challenge.

Survivalist Hazen Audel faces fetid swamps as he completes his final survival challenge.

In Port Protection, only few succeed in bringing home nature's bounty.

In Port Protection, it takes bush ingenuity to prepare for the coming freeze.

The citizens of Port Protection give back to their community.

Sam and Matt Carlson brave chilling conditions on their final mission for deer.

The villagers of Port Protection are back to paving with good intentions.

Curly shoots a bear; Troy and Sarah struggle with a new water system.

Residents tackle tasks at the height of summer's season of productivity.

In this enhanced episode, Port Protection neighbors lend a helping hand.

Port Protection residents prioritize the greater good of the community.

Alaskans teach their children the ways of the wild.

In this enhanced episode, Port Protection neighbors lend a helping hand.

Jo Roger and Ole Henrik struggle to rescue a trailer load of salt that threatens to pollute Norway's biggest salmon river.

Alaskans push their limits amid the warming tundra and melting landscape; Chip Hailstone builds a blind in hopes of a successful first-of-the-year hunt.

In Alaska, the transition into spring is marked by longer days, open waterways and returning wildlife; Sue Aikens finally returns home to Kavik.

Alaskans must overcome rising waters in order to capitalize on spring's offerings.