The Peloponnesian League, led by Sparta, defeated Athens in the Peloponnesian War.

The conflict formerly began in 431 BCE following the collapse of the previous Thirty Years’ peace between Athens and Sparta. As the two dominant powers in Greece, the city-states each led alliances of other independent territories in the area. The Athenian empire had the stronger navy due its location on the Aegean Sea, while the Peloponnesian League under Sparta had the stronger land army.

The contemporary historian Thucydides wrote an extensive account of the tensions between the two powers, and claimed that the war began due to Sparta’s concern at the growing power of Athens. In 431 BCE Sparta launched the first of many invasions of Attica under the command of the Spartan king Archidamos. This signalled the start of the first of three phases of the Peloponnesian War that engulfed much of the Greek world and left the Athenian empire in tatters.

During the first phase of the war, known as the Archidamian War, Sparta benefitted from an outbreak of the plague in Athens. This killed the leading Athenian general, Pericles, along with up to two-thirds of the population of the city. Although Athens went on to mount some successful offensives the two sides agreed to the uneasy Peace of Nicias in 421 BCE.

The war resumed in 415 BCE, after which Athens launched a disastrous attack on Syracuse in Sicily. Subsequent years saw Sparta build its own naval fleet with financial support from Persia, and it was with this that they were able to destroy Athens’ fleet at Aegospotami 405 BCE. Athens surrendered the following year, dramatically altering the balance of power in Greece.

On the 24th April 1916, Sir Ernest Shackleton and five companions set off in the James Caird, a recovered lifeboat, to sail from Elephant Island to South Georgia in the southern Atlantic Ocean.  Their mission was to organize a rescue party for the shipwrecked crew of the Endurance.

The crew had been forced to make their way to Elephant Island after the Endurance sank due to pack ice the previous October.  Having made their way off the ice in the Endeavour’s lifeboats at the start of April, Shackleton decided to take the strongest lifeboat – the James Caird – on the perilous mission across the Southern Ocean to South Georgia.

Despite all the odds stacked against them, the crew of the tiny boat reached South Georgia in 16 days.  A smaller team of three, led by Shackleton, then had to undertake a 17-mile, 36 hour journey by foot across South Georgia’s mountainous interior to reach the whaling station at Stromness where they summoned help.

Historian Carol Alexander has since said that the voyage of the James Caird is one “one of the greatest boat journeys ever accomplished.”  However, the final word on the achievement of the crew must go to Shackleton himself.  In “South: the story of Shackleton’s last expedition 1914-1917” he said this:

“We had suffered, starved and triumphed, grovelled down yet grasped at glory, grown bigger in the bigness of the whole…We had reached the naked soul of man.”

Duke Wilhelm IV of Bavaria signed the Reinheitsgebot, a law to ensure the purity of beer that specific a limited number of ingredients.

The early 1500s experienced economic and agricultural tensions which saw brewers and bakers competing to purchase grain to produce their goods. In an effort to avoid price inflation, the Reinheitsgebot consequently limited brewers to only use barley while wheat and rye were exclusively made available to bakers for bread.

The original purity law was signed in Ingolstadt and stated that beer brewed in Bavaria could only contain barley, hops and water. As the political situation in Germany changed over the subsequent centuries the Reinheitsgebot continued to be a central piece of legislation. Its pan-German implementation was even a prerequisite for Bavaria joining the German Empire in 1871. The strict nature of the law meant that it has often met opposition from some German brewers leading to some adaptations. These include recognising that yeast is required for fermentation, and permitting malted ‘grains’ rather than just barley to be used.

Despite the subsequent changes, some people have blamed the Reinheitsgebot for the lack of diversity in German beers. As recently as 2016 the German daily newspaper Der Spiegel criticised the law for denying brewers the opportunity to experiment with new ingredients and styles. Consequently some breweries have begun to create brews that don’t follow the law, but they are not allowed to call them ‘beer’.

Meanwhile the Reinheitsgebot continues to have a number of supporters, and German beers brewed to its specifications have the status of a protected traditional foodstuff under European Union law.

On the 22nd April 1915, the Second Battle of Ypres began in Belgium.  The battle has become most remembered for seeing the first use of gas in the First World War, but Second Ypres really marked its first effective use.  A form of tear gas had previously been used by the Germans fighting the Russians at Bolimov in the east 3 months earlier, but it had proved wholly unsuccessful.  The freezing temperatures meant that a lot of the gas failed to vaporize, and that which did got blown back towards the German trenches.

At Ypres, the situation was dramatically different.  5,700 gas canisters were released by hand, all of which contained highly poisonous chlorine gas.  The Germans relied on the wind to blow the gas towards their enemy but, despite some German casualties due to the rudimentary system of release, the gas was terribly effective.

Over 5,000 French Algerian, Moroccan and territorial troops died within ten minutes of the gas being released.  A further 5,000 were temporarily blinded, with nearly half of them becoming prisoners of war.

The Germans didn’t expect the gas to be as effective as it was, and so didn’t fully exploit their initial advantage.  However, by the end of the battle on 25th May, the Germans had certainly scored a tactical victory.  They had compressed the size of the Ypres salient and had demonstrated the effectiveness of chemical warfare.  The Allies soon developed their own poison gas, making chemical warfare part of the offensive strategy for the rest of the war.

The German fighter pilot Baron Manfred Albrecht Freiherr von Richthofen, better known as the Red Baron, was shot down and killed.

Richthofen was born into the German aristocracy in 1892. He began military training when he was 11 years old, and served as a cavalry reconnaissance officer in the early months of the First World War. However, the advent of trench warfare made the cavalry virtually obsolete and his unit was disbanded.

Frustrated at being reassigned to non-combative roles, Richthofen applied to the Imperial German Army Air Service and was granted permission to join in May 1915. Having begun as an observer on reconnaissance missions, he began to train as a pilot in October and joined one of the first German fighter squadrons the following year.

Richthofen quickly gained a reputation as a formidable fighter pilot. Having scored his first confirmed victory on 17 September 1916, Richthofen went on to shoot down a total of 80 enemy aircraft although only 19 of these were made in the red Fokker Dr. I triplane that is commonly associated with him. As a squadron leader Richthofen ensured that his squadron followed the Dicta Boelcke, a series of formalised tactical rules for air combat that had been developed by his mentor, Oswald Boelcke.

Richthofen was fatally wounded over Morlancourt Ridge near the village of Vaux-sur-Somme. Despite the single bullet severely damaging his heart and lungs he managed to land his aircraft in a field before he died. He was buried with full military honours by No. 3 Squadron of the Australian Flying Corps in France, although his remains now lie in Richthofen family grave.

On the 20th April 1965, workers began painting skylight windows at the Houston Astrodome to limit glare from the sun.  The covered stadium, the first of its kind, was built in order to avoid the need to cancel sports fixture as a result of the hot, humid, and therefore often rainy Texas summer.

The stadium had cost nearly $32 million to build, and the painting of the skylights added another $20,000 dollars to the cost.  The paint job had been made necessary due to glare from the windows affecting the vision of baseball outfielders.  Painting the windows significantly improved the situation for the player, but in turn led to other problems for the Astrodome.

Primarily, the up-to 40% reduction in sunlight making its way inside the structure meant that all the specially-bred Bermuda grass used for the field died.  This was despite the owners originally believing that painting the windows might actually improve the growth of the grass, since it had been formulated to grow indoors.  Left with no grass, they resorted to a second paint job in which they painted the dirt floor green, until they installed artificial turf the following year.

That turf was called ChemGrass, a hardly inspiring name, so following the successful use of it in the 1966 baseball season at the Astrodome the company rebranded it.  And thus AstroTurf was born – an artificial grass that got its name from an indoor sports stadium.

The Treaty of London was signed, which recognised and guaranteed the independence and neutrality of Belgium.

In 1813 Napoleon’s rule of the Netherlands was ended by the combined armies of Russia and Prussia, and control was given to William Frederik of Orange-Nassau. Two years later, as a result of the Congress of Vienna, modern Belgium became part of the United Kingdom of the Netherlands.

These southern provinces were predominantly Catholic, and a sizeable number of the inhabitants spoke French. However, William clearly favoured Protestantism and had tried to impose Dutch as the official language. This led to tensions which were exacerbated by economic problems that included high unemployment and arguments over the effect of free trade on the less developed south. A revolution erupted in 1830 that led to the states declaring independence on 4 October, although William refused to recognise the independent Belgium for over nine years.

In signing the treaty that formally recognised the existence of the independent Kingdom of Belgium, the Netherlands were joined by Britain, Austria, France, Russia, and the German Confederation. Furthermore, Britain insisted that the signatories also recognise Belgium’s perpetual neutrality.

The neutrality clause was of central importance in the outbreak of the First World War, since Germany violated Belgium’s neutrality when its forces crossed the border in the Schlieffen Plan. Britain thus claimed to be upholding the Treaty of London when it declared war on 4 August 1914 – much to the anger of German Chancellor Theobald von Bethmann-Hollweg who couldn’t believe Britain would go to war over a ‘mere a scrap of paper’.

On the night of 18th April 1775, Paul Revere rode from Charleston to Lexington with his message that “the Regulars are coming!”  The action that was to signal the start of the American Revolutionary War has passed into legend, but whether he referred to the approaching army as ‘Regulars’ or ‘Redcoats’ is unclear.  However he certainly didn’t say that the British were coming.  At the time the American settlers would still have seen themselves as British, albeit living in a colony and ruled by a faraway King.  It’s also highly unlikely that Revere shouted his warning as he passed peoples’ houses.  His mission was secret, and the countryside was known to contain army patrols and royalist sympathisers.

By the time British troops entered the town of Lexington the next morning, 77 militiamen had assembled.  Their leader, Captain John Parker, knew that his men were outnumbered and so gave an order that is now engraved on a stone at the site.  “Stand your ground; don’t fire unless fired upon, but if they mean to have a war, let it begin here.”

The leaders of both sides ordered their men not to fire, but a single shot from an unknown source rang out.  The Battle of Lexington lasted for just a few minutes, killing eight militiamen and wounding a further 10.  Moving on to the town of Concord, however, the British met significantly more opposition.  The American Revolution had begun.

The Bay of Pigs Invasion was launched by the CIA-sponsored paramilitary group Brigade 2506.

The invasion saw over 1,400 American-trained Cuban exiles attempt to overthrow Fidel Castro. Castro had come to power in 1959 during the Cuban Revolution which toppled the previous president, General Fulgencio Batista. The new government quickly began introducing agrarian reforms and nationalising US-owned interests. These actions led to the USA imposing a trade embargo against Cuba from late 1960, after which Castro began to further develop his relationship with the USSR.

As concerns grew over these developments, US President Dwight D. Eisenhower authorised the CIA to begin devising a way to overthrow Castro. He allocated $13.1 million for them to begin training counter-revolutionary Cuban exiles and, on 4 April 1961, his successor John F. Kennedy authorised the final invasion plan.

While the seaborne invasion force gathered in Guatemala, a smaller group of Cuban exiles attacked Cuban airfields on 15 April using CIA-obtained B-26 bombers painted to appear like they were captured Cuban planes. That evening the Cuban government tabled a motion to the United Nations, accusing the United States of being behind the attacks. Consequently a series of airfield attacks planned for the early hours of the 17 April were cancelled by Kennedy.

The amphibious assault went ahead as planned but quickly began to go wrong. The exiles from Brigade 2506 were pinned on the beach by a counterattack from the Cuban Army and assorted militiamen, leading to 114 exile deaths and the capture of over a thousand others. In the aftermath, Cuba developed even closer links with the USSR that led to the Cuban Missile Crisis the following year.

On the 16th April 1922, former First World War enemies Germany and Russia signed the Treaty of Rapallo.  Both countries had been excluded from the League of Nations, and this acted as a catalyst for the pact.

The Western powers were startled by the agreement.  When Germany drew up the harsh Treaty of Brest-Litovsk in 1918, Russia had been forced to sign away large swathes of land.  The Treaty of Rapallo meant the two countries abandoned all territorial and financial arguments stemming from Brest-Litovsk and, instead, to “co-operate in a spirit of mutual goodwill in meeting the economic needs of both countries”.

The Treaty of Rapallo was particularly important for Russia, as it was the first international recognition of the Bolsheviks as the official government.  However, it was the military clauses – most of them secret – that were most valuable to both sides.  German factories producing military goods were able to move to Russia, effectively bypassing the Treaty of Versailles limits on German weaponry.  Furthermore the two armies conducted joint training exercises deep inside Russia, which enabled the German army to continue to use technology banned by Versailles such as tanks and war planes.

Russia benefited from this agreement as well.  They were able to see Western European military technology, and work with German engineers who shared techniques that were to be the bedrock of Stalin’s Five Year Plans.

The Rapallo Treaty alarmed the Western Powers, but the danger was short-lived.   By the middle of the 1920s, Germany under Stresemann had begun to improve relations with them as a result of the Locarno Treaties, meaning a close relationship with Russia was less vital.