The Last Ship is the tenth episode of the fourth season of Vikings. It is the thirty-ninth episode of the series overall. It first aired on April 21, 2016. It was written by creator Michael Hirst and directed by Jeff Woolnough.
On the river, a fleet of Frankish ships approaches the Vikings, with Rollo leading the way. In Paris, Charles has Roland and Therese executed, while Gisla says prayers for Rollo. The Vikings and Franks battle on the river, with the Vikings defeating the first fleet of French ships. Rollo then leads his remaining ships into a bloody battle. Halfdan, Floki, and Lagertha are all wounded. Ragnar and Rollo begin to battle and come to a stalemate. The Franks win the battle, and Ragnar tells Bjorn to take Lagertha and retreat to the ships. Ragnar charges Rollo, but is grabbed and thrown into their ships, as they sail away in defeat. Rollo is greeted by Charles and Gisla, and crowned to the applause of Paris.
In Kattegat, ten years pass. Ragnar has disappeared. A messenger delivers news to Aslaug and Bjorn that the Viking settlement was slaughtered, and that Ragnar has a son named Magnus in Wessex. Bjorn tells his brothers, who now resent Ragnar. Bjorn prepares to sail into the Mediterranean. Shortly after, Ragnar returns to Kattegat a hated man, and challenges his sons Ivar, Ubbe, Hvitserk, and Sigurd to kill him if they want to be king.
- Travis Fimmel as King Ragnar
- Katheryn Winnick as Lagertha/Earl Ingstad
- Clive Standen as Duke Rollo
- Gustaf Skarsgård as Floki
- Alexander Ludwig as Bjorn
- Alyssa Sutherland as Queen Aslaug
- Lothaire Bluteau as Emperor Charles
- John Kavanagh as The Seer
- Peter Franzén as King Harald
- Jasper Pääkkönen as Halfdan
- Maude Hirst as Helga
- Alex Høgh as Ivar
- Marco Ilsø as Hvitserk
- David Lindström as Sigurd
- Jordan Patrick Smith as Ubbe
- Georgia Hirst as Torvi
- Morgane Polanski as Princess Gisla
Additional Cast (in order of appearance)
- Tom Hopkins as French Archbishop
- Ian Meehan as Frankish Officer
- Huw Parmenter as Count Roland
- Karen Hassan as Therese
- Adam McNamara as Thorhall
- Hannah Behan as Shield-maiden
- Lianne Bowley as Shield-maiden
- Katie Castle as Shield-maiden
- Jordan Coombes as Shield-maiden
- Amy Donnelly as Shield-maiden
- Aisling Goodwin as Shield-maiden
- Celine Nihicidhe as Shield-maiden
- Kevin Durand and Linus Roache are not credited and do not appear in this episode.
- Further evidence that Ivar might be suffering from "brittle bone disease" is his blue eyes. The name for this disease is Osteogensis imperfecta, which is characterized by fragile bones, conductive hearing loss, and blue sclera, meaning the white portion of the eye is blue.