On the southeast edge of Eisenach, Germany, there is a steep hill. On top of that hill sits a fortification, a castle. It is not one of those popular fairy tale castles like Neuschwanstein in Bavaria – though there is a link between Neuschawnstein and this castle – rather it has working origins. It is a Burg not a Schloß.

But this castle, the Wartburg, has had a major role in shaping the western world; it was there, at the Wartburg, where Martin Luther translated the New Testament into German, while Luther was hiding from Catholic authorities.

The Wartburg also hosted a singers competition in its Singer’s Hall, from which Richard Wagner’s opera, “Tannhäuser” was derived – and the Singer’s Hall was the design inspiration for the Music Hall in Neuschwanstein.

And the castle lent its name to an automobile built in the little town below. In the late 1920s the owners of that automobile company were looking to sell. Germany had been through political and economic crises – consolidation had hit the automotive industry hard, Opel was purchased by GM, the Daimler-Benz merger occurred, and Laurin & Klement – who started out by making bicycles – was absorbed into the old Czech arms manufacturer, Škoda.

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BMW had experimented with automobiles and had decided not to build a luxury or near-luxury car due partly to the economic conditions. The problem was that German middle class savings had been wiped out during the hyperinflation of the early ’20s, the market for luxury cars was only so big – not growing – and was already well covered. Another important issue, not always noted, is that Daimler-Benz was a major shareholder of BMW stock at the time and would not have taken kindly to BMW competing on their own turf.

The problem of hyperinflation, however, was in the past and there was hope of recovery – even though, unbeknownst to most, the Great Depression loomed on the horizon. That glimmer of hope gave some succor to sales of small cars though. And for the Fahrzeugfabrik Eisenach’s hoped for recovery the Dixi line was enhanced with a license built Austin 7, a minimalist small car originally made in Great Britain.

Like L & K, Fahrzeugfabrik Eisenach had started by making bicycles, then moved on to motor carriages under the Wartburg brand name – and eventually the Dixi name, Dixi being Latin for ‘I have spoken’. There had been some success and military contracts during World War I – but the economic buffeting, and political uncertainty of the ’20s caused problems.

BMW was having success with aero engines, the acclaim of the mighty IIIa and IV inline six engines sustained sales – and through the 1920s the Soviet Union was purchasing aero engines. BMW continued to make water cooled aero engines, including the VII (a direct injected V12) and the VIII (a four valve per cylinder inline six) -, and also experimented with a supercharged V-12, the IX.

But the chance to enter the automobile market presented itself when an owner of the Fahrzeugfabrik Eisenach, known to Camillo Castiglioni, offered it for sale and BMW grabbed the opportunity. The German variant of the Austin 7, the Dixi 3/15, thus became the BMW 3/15.

The Dixi 3/15 wasn’t much – a tiny car with a flathead inline four cylinder engine. But it sold well and provided a platform which could be improved. BMW set about improving the front suspension, fitting larger steel bodies manufactured by Ambi-Budd – and later by Daimler-Benz, and updated 4 wheel brakes. But the license to build the Austin 7 clone was to run out in 1931 and BMW, prior to the license expiration, begin designing and then building its own cars in house. Germany was building about 100,000 cars a year in the late ’20s, BMW built between 6 to 8 percent of them in ’28 and ’29 – and that was incentive enough to continue producing them.

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As the Austin license was expiring BMW came out with a new car designed in-house, the 3/20, It employed a swing axle independent rear suspension, OHV four cylinder equipped and was equipped with a four speed gearbox. BMW then launched the 303 in 1933, a pure BMW design. The 303 was the first BMW to sport the kidney grille and also an inline six cylinder engine. When BMW created the 309 four cylinder in 1934 there were, at last, only a few bits left from the Dixi 3/15 still incorporated in the vehicle.

The new car models came in a flurry during the ’30s; the 315 in ’34; the 319 in ’35; the 326 in ’36; and the 320 and 327 in ’37. In that mix add the 325, a military specification all wheel drive off-road vehicle, and the vaunted 328. The 328 was intended for an assault on the racing scene, the 319 was getting long in the tooth and BMW wanted an upgrade.

The problem facing BMW is that even though engineering was being done on a potential DOHC six cylinder, they were running out of time and money. The end result was a very weird OHV cylinder head used on an existing short block.

To make everything work, given the reuse of the pushrod gallery from the existing short block, required that the exhaust valve pushrods come up on the intake side of the head and operate a bell crank. The bell crank then operated a horizontal pushrod (that extended across the head) which moved a rocker arm that opened the exhaust valve. Monkey motion in the extreme.

Regardless of its weirdness, it worked well and the 328 spawned a number of great sports racers including some lovely Touring bodied cars. (It was the Touring bodied BMW 328 roadsters that would lend their styling lines to the post-war Jaguar XK120.)

Motorcycles were still in demand and the Munich plant produced new models, improvements on the already well regarded machines. In 1928 over 5,000 R52s had been sold and BMW was moving to produce motorcycles using a pressed steel frame, which saved production costs but more importantly eliminated the cracked tube issues they experienced on previous models. It was the boxer engine, propshaft, and pressed steel frame that defined what a ‘German’ motorcycle was. BMW motorcycles were well regarded and could command a higher price.

In 1930 the R11 tourer and R30 sport model were introduced. In 1931 the single cylinder R2, a 200cc motorcycle – skirting licensing and road tax costs – proved a good seller. The follow on R4 in 1932 was a 400cc single cylinder model and between 1932 and 1936 15,000 R4s were sold. One less than ideal model was introduced in 1936, the single cylinder R300 – but it was quickly superseded by the better R350.

The R11 and R30 were powered by a 750cc boxer motor, the 500cc boxer being shelved. But in 1935 BMW revived the 500cc boxer in the R5 and later upped the capacity to 600cc in the R6. In the late 1930s they also updated the single cylinder models with the addition of the R20 (200cc) and R23 (250cc). BMW continued to burnish the image of its motorcycles by racing and winning races with them.

In 1934 the National Socialists came to power in Germany, under the increasingly dominant influence of Adolph Hitler. Germany had been wracked by economic crisis in the early 1920s, as hyperinflation ate away at the economy. The political situation was no better, there was strong sentiment on one side that Germany had been betrayed at the end of the Great War and armed conflict in the streets between communists and right wing parties eroded confidence in government. And Germans were looking for a knight in shining armor – someone that would restore confidence and bring opportunities to the lower middle class.

It was in the succeeding years that the National Socialists’ constrictions on production priorities for manufacturing firms tightened as the various Reich ministries implemented a command economy. For BMW that meant increasing military production, at the expense of consumer products. And BMW would feel the noose of National Socialism tighten around how and what aircraft engine production would be allowed.

Into the 1930s BMW continued to build water-cooled aircraft engines, inline sixes and V-12s. They even experimented with a couple of inverted V engines – the BMW XII (116) and XV (117). Inverting the V allowed for a better ‘greenhouse’ for the pilot (a better view over the cowl) than a regular V and given that fuel injection was available there were no issues with running the engine essentially upside down. These engines were submitted for type acceptance in 1936 but the German Aviation Ministry asked that they be pulled. The government wanted BMW to concentrate on radial engines.

BMW had purchased a license to produce copies of Pratt & Whitney’s Hornet radial engines in 1928. They had previously reconfigured a boxer engine for very light aircraft use and were intrigued by the power to weight ratios air-cooled aircraft engines allowed. BMW’s modified Hornet, the 128, was quickly replaced by the improved 132. And variants of the BMW 132 graced some very popular airplanes, in particular the Junkers 52 – Ju-52/3 – the much loved ‘Tante Ju’. BMW also experimented with a radial diesel engine; diesel having been selected due to issues with gasoline quality, but that was shelved in 1937.

During the time that BMW was absorbing the Fahrzeugfabrik Eisenach in 1928, Siemens was establishing a separate company to handle the manufacturing of aero engines in the Berlin suburb of Spandau. In 1936 the enterprise was cast free from Siemens and became known as the Brandenburgische Motorenwerke, Bramo. Siemens had licensed the Jupiter radial engine from the British company, Bristol. It received continuous developments through the 1930s and evolved into a nine cylinder, direct injected, two stage supercharged radial engine with the designation 323, known as the ‘Fafnir’.

And the German Aviation Ministry stepped in and insisted that Bramo and BMW agree to exchange engineering information on the development of radial engines which eventually, in 1939, led to BMW absorbing the Bramo operation.

BMW now had operations in Bavaria, Thuringia, and Brandenburg. They were building well regarded motorcycles and cars and, given the intervention of the German Aviation Ministry, they had abandoned inline aero engines for radial engine development. 1938 was a watershed year, as Europe stood on the abyss – Neville Chamberlain’s pronouncement after the 30 September 1938 Munich agreement of, ‘peace for our time’, would prove to have a short shelf life. German companies with any hooks into arms manufacturing were now essentially being controlled by Berlin and that included BMW.