Once Nelson & the fleet had won at Trafalgar there wasn't an intact navy left that could challenge the British Navy. The French did try & build back up, but the British managed to always go one better & build more or better ships - this was the first "arms race". The Empire used this naval superiority to behave badly and make money, in much the same way that the Empire used any other sort of technological edge they had. As an example - once they'd their steam driven gunboats to slaughter the Chinese fleet, the British annexed the island of Hong Kong and always kept a few gunboats sitting in the harbour there to make sure to remind the Chinese government what would happen if they got any funny ideas about stopping trade with Britain. This is the origin of the term "gunboat diplomacy".
But the lack of any challenge had a detrimental effect on the Navy over time - after a while there was no-one who'd actually had to fight in a real war. And in peace time it was harder to rise from the ranks to become an officer, as the traditional way to do so was to demonstrate valour in combat. This meant the hierarchy fossilised - the officers came from the "right families" and no matter how talented a rating was he wasn't getting promoted. The best demonstration of how big a problem this was is the collision between HMS Victoria & HMS Camperdown. The fleet in the Mediterranean were doing manoeuvres and the senior officer (commanding the Victoria) signalled for a particular course change, the officer in charge of the Camperdown hesitated because it looked unsafe (due to the proximity of the battleships and the size of their turning circles) but was signalled to get on with it. He obeyed his orders, and the two ships collided - more than 450 lives were lost, including the commander on the Victoria. The subsequent court martial didn't completely clear the commander of the Camperdown of blame, but did say that the vast majority of the blame fell on the shoulders of the senior officer because "of course" the other officer should have followed orders. (Reading wikipedia about it while writing this post it's become obvious that the programme simplified things almost to the point of being wrong - I was left with the impression after watching it that the commander of the Camperdown was regarded as having done the right thing in obeying orders, but the situation appears to be a lot more nuanced than that).
By the start of the 20th century there was a new enemy - the Germans were starting to build up their fleet to try & challenge the might of the British Navy. This lead to a new arms race, and the British designed & built the first dreadnoughts. Counter-intuitively these powerful ships actually levelled the playing field - they were so much better than the older ships that all that mattered was how many dreadnoughts you had. And everyone was starting from a point of having few or none. The British did manage to ramp up production of the ships, and by the start of the First World War had twice as many ships as the Germans. The two fleets met in battle off the coast of Denmark - the last great battle involving battleships. The British lost. In large part due to their own mistakes. One of these was that the ships had radio but this wasn't used because it was too new-fangled for old fashioned commanders who'd rather rely on flag signals. The conditions weren't good for visibility (hardly surprising when every ship is belching out smoke) and the misinterpreted or un-understandable signals caused confusion. There were also losses of ships that could have been avoided - safety hatches in the ships were left open between the guns and the ammo stores, and several ships blew up when German shells dropped straight down into the ammo and ignited it.
Snow then finished up the programme with a brief trot through the overall shape of the Navy's history - from collection of ships barely working together through to a fleet that was if anything too regimented & regulated. He briefly mentioned the more modern role of the Navy in protecting shipping and providing mobile aircraft bases, but really what he'd been interested in telling us about in this series was the big naval battles phase of history. When our investment into the Navy allowed a small island to control an enormous empire, before technology moved on and left us behind again.
The second programme we watched was presented by Rachel & Rebecca Unthank, the singers in The Unthanks, called "The Unthanks: A Very English Winter". The two women travelled around the country attending traditional events associated with dates in the winter. So for instance for Bonfire Night they went to Lewes, where they take the whole thing very seriously indeed! Imagine Mardi Gras, but with a lot of fire & politics. There are still Mummer's Plays done in various places throughout the year, and they had longsword dancing and molly dancers (not morris dancers though, but this was clearly the same type of thing). A programme to watch for the spectacle and the songs, and also coz it's nice to see there are still some old-fashioned traditions carrying on into the present day :)