King Alfred the Great was such an impressive English king that he's literally the only monarch in the nation's storied history to have ever been given that particular handle. Yes there were other fantastic leaders who've gone by "The Great", (Alexander, what what?), but Alfred had earned this particular title for the might he displayed against Viking invaders after he took the throne in 871 AD.
The Last Kingdom chronicles his martial exploits, along with the sickness that afflicted King Alfred.
Even before Alfred officially became king he was fighting Vikings and helped clock in some significant victories for the English to protect both him and his Celtic brethren from the terror of the men in the North.
By the year 878, Wessex was the only kingdom in the region that hadn't fallen to "The Great Heathen Army". Alfred managed to rally his remaining troops in marshes where they fought strategically against the Danes.
They ultimately won a key battle at Edington after regrouping at Egbert's Stone. This allowed Alfred the chance to negotiate for peace, which he did, even if a few little skirmishes and mini-battles still persisted long afterwards. It also afforded him the opportunity to restore Wessex to its former glory, which he did with the help of his people.
But fending off the Vikings during his time as king wasn't the only major exploit Alfred accomplished.
You know how the English Navy was pretty much the greatest aquatic military power for the longest time? Yeah, Alfred laid the groundwork for not only that but England as a country period. He also promoted education among the English people and helped establish a fair system of law and order that would persist in the land long after his reign was over in 899. Not bad for less than 30 years in charge, right?
What sickness does Alfred suffer from in 'The Last Kingdom'?
While any type of illness prior to the mid 1900's was pretty much cause for concern, what Alfred was reportedly fighting, according to historians, was very, very serious: Crohn's disease. An inflammatory bowel disease (IBD), the symptoms of Crohn's vary, but those afflicted with it can suffer from a multitude of different conditions. In the show, Alfred's shown as being particularly weak and waifish.
This could be attributed to his inability to eat, as one such symptom of the disease is not only a loss of appetite, but an inability to properly digest food as well, which could also explain the rapid weight loss several of those afflicted with Crohn's suffers.
There's no way to know for sure exactly what sickness Alfred was ailing from, however, if we're to believe historians, from all accounts it certainly sounds like Crohn's.
"The Middle Ages" is kind of an absurd term, as it accounts for nearly 1,000 years of known human existence. But some of the most prominent diseases and illnesses at the time were dysentery, tuberculosis, arthritis, and "sweating sickness", which was influenza.
There were also tons of skin conditions that plagued individuals as a result of poor hygiene practices during this time.
Animal carcasses would be left to fester in the street and cesspools filled with human waste would routinely be found in cities and towns. Having access to clean, running water was also a huge problem for most individuals. Working class folks also would typically bathe/shower in cold water without soap, which isn't exactly the best case scenario for someone who's trying to stave off disease, bacteria, or infectious disease.
It also didn't help that the majority of homes would use hay or grass as a makeshift "carpet" for domiciles. The problem is that this organic material would rot after a while and become a hotbed of germs and in many cases, pests and parasites. Living in the Middle Ages was just a generally gross and nasty time.
The Last Kingdom doesn't really get specific what Alfred's suffering from, which is historically accurate because there's no way folks would have known back then what the disease was. Props to the BBC for getting all of the specifics down, however, even if the specifics weren't so...uh...specific.