The intervention of military forces from Nazi Germany and Mussolini's Italy, particularly the aerial forces of the German Condor Legion, showcased the new deadly possibilities of aerial warfare on the civilian populace of, thinking regionally, a European nation.Long before the crisis of abdication, Spain had been ruled by a military dictator, the aristocratic general Miguel Primo de Rivera (d.1930) who came to power during the Rif War. Another critical event in the increased amount of anti-government resistance before the Civil War from the left & right was the Asturian “Revolution” of 1934. Miners went on strike in the northern Basque region of Asturia proclaiming a 'Red' state- threatening as many in the army felt, to carry the flag of Bolshevik idealism into the heart of the Spanish Republic.
The military, which was staunchly anti-Bolshevik reacted instantly. Republican forces quickly moved to the area and government troops showed no mercy in brutally putting down the rebellion with help from local mining bosses who aided in the capture and execution of the supposed ring leaders of the revolt. The revolution had been quickly put down but the outrage from the left was particularly strong thereafter.
Formation of the Condor Legion
German interest peaked in
following the creation of the fascist party the Falange Española or the Spanish
Phalanx in 1933, eventually led by José Antonio Primo de
Rivera, the son of the late dictator. By the beginning of August 1936, the prospects for a
successful Nationalist rebellion seemed dim without intervention from a major power. Franco now confirmed as
Commander-in-Chief of the rebels had many well trained troops waiting in Spain Morocco
but was unable to transport them to the mainland without suitable air craft or naval vessels to do so.
The republicans had retained most of the air force and naval vessels so diplomatic cables were quickly dispatched by Franco to the two major fascist powers in the region,
for immediate, and if possible substantive aid. Nationalist military representatives flew from Morocco and on the evening of the 25th
of July touched down in Germany.
Greeted by Rudolf Hess in Berlin the Spaniards
were quickly taken to meet with Führer
Adolf Hitler in Bayreuth.  Also in attendance at this meeting, war Minister Werner von
Hermman Göring, and Vizeadmiral Erich
Raeder. Most of the talk in this meeting was solely on the military means and possible
strategy that could be used by the Luftwaffe
and the Heer in aiding the
Nationalists. It was decided almost immediately by Hitler that the Germans
would intervene and send war materials immediately for the defeat of communism
so close to Germany and Italy somewhat,
and in the hopes of installing another fascist country near the much hated
French. Hitler was not necessarily thinking of a global
revolution in which fascism would eventually control almost half the world as
communism did under the USSR and under Chinese influence later would during the
Cold War, but he was certainly aware of the problems a communist allied nation
may present to Germany
The Condor Legion arrives in Spain
The Italians under Mussolini had already supplied several bombers before German aid had arrived at the
in the early morning hours of the 6th of August. This aid began in
earnest with only several working Ju 52 transport craft arriving in the first
week. German flying crews in port of Cadiz Spain reluctantly obeyed the order
to not take part in any combat sorties but to instead serve as advisors to the
Nationalist crews, train them in the use of the He 51 and Ju 52, and fly
transport and reconnaissance missions if needed.
In fact all German crews in the first weeks of the war were dressed as civilians and had to hide any and all military insignia. In particular, a written decree was handed down specifically forbidding the use of the swastika on any German or Nationalist equipment. Hitler skirted international by enlisting Nazi officials to make “donations” to these private army in the form of bullets, incendiary bombs, and other materials needed for immediate aid to their Spanish comrades. The Ju 52’s were critical to supplying the Nationalists on the mainland and more importantly transporting the hardened Moroccan and other Legionaries in Franco’s Army of Africa. The Spanish did surprise their German advisors by scoring their first victories rather early in a He 51 on August 18th. 
The training of Spanish Flak gunners was also vital to the Nationalist rebellion and many hundreds of German made 20mm Flak cannons would be used during the conflict. As always the unsung heroes of the ground crew were the more numerous and needed personal. In terms of tactics, great ingenuity was showed by the Luftwaffe leadership early on, a notable example being Captain Rudolf Freiherr von Moreau who outfitted two Ju 52’s each with six 250 kg bombs and optic bomb-sights for a potential raid in an attempt to lift the Republican naval blockade. Von Moreau led the aircraft in raid on the coastal city of
Málaga in southern Spain.
Nationalist Ju 52 displaying the Spanish Falange 'yoke & arrows' symbol
Though he was unable find his target due to bad weather, von Moreau’s operation was a tactical success when the other air crew did successfully attack the Republican dreadnought Jamie I, causing serious damage to the ship. The first sorties were flown over
several weeks later on the 23rd of August and by early September
1936 the air war over Spain
had officially begun.
On the 31st of October Generalmajor Hugo Sperrle took command of the Condor Legion and departed for
Gaining experience and perspective as an officer in the German Imperial flying
corps, Sperrle was a dedicated student of the potential power of aerial
warfare. He wasted no time in organizing the Luftwaffe for a limited but extended campaign-By
mid November 1936 the Legion had officially arrived in Cadiz
setting up their forward base in the City of Sevila.
General Hugo Sperrle (b.1885-1953)
The Legion had for the most part been successful in accomplishing its early objectives of direct support to the Nationalists though many of the enlisted German airmen quickly grew impatient with the war and perceived lack of attention from
Several Condor Legion plane artwork-the use of the
Iron Cross and Swastika was frowned upon by officers and diplomats Berlin
This early success was due in part because the Soviet made Polikarpov I-16 and their experienced pilots. Known as the Rata (Spanish for rat) by the Germans, the I-16 was highly successful at challenging the Condor Legion’s aircraft in the first two years of the intervention, indeed it was the superior machine in the skies. Almost 30 miles per hour faster than many of its German counterparts even Generalmajor Sperrle noted in a report dated in 1937 that after the “technically superior Russian [Polikarpov I-16] fighters” had made themselves noticed, the combined Nationalist “losses climbed and the Reds gradually won air superiority.” 
The Tupolev SB was another breakthrough Soviet technology, its capabilities as lightly protected bomber with a relatively fast top speed was another important milestone in aerial warfare. This machine would be used to great effect in the 1939 Nomonhan conflict with the Imperial Japanese army on the border with Mongolia.
For the Luftwaffe, 1937 was an important year because of the phasing out of the older style planes like the Heinkel HE 45 and HE 60 which both had open cockpits and still closely resembled the planes of World War I and of the interwar. The arrival of the Messerschmitt BF 109 in late 1936 gave the Condor Legion a plane which could finally out-fly, out-maneuver and more importantly, out-gun its communist counterparts.
Though they could be used for dogfights the BF 109 proved its worth with a less glorious task, escorting the lumbering German bombers like the Ju 52. Its arrival helped to curb the Republicans ability to attack them at will in their Ratas. This protection allowed for the bombers to now hit their targets with an increasingly higher rate of success, destroying aircraft and armor from the sky much more frequently, drastically cutting the number of mechanized weapons available to the Republicans.
The Junkers Ju 87 or Stuka, made their appearance around the same time as well. As a result of their introduction by late 1937 and into autumn of 1938, dive bombing tactics which would give the Blitzkrieg its signature ferocity, practiced and refined by the Condor Legion during the Spanish Civil War.
Part II, Achtung Panzer in Spain: Bombing of Guernica 1937 and the Withdrawal & Lessons of the Condor Legion
 Ries, Karl Ring, Hans The Legion Condor: A History of the Luftwaffe in the Spanish Civil War pgs. 7-9
 Ries, Karl Ring, Hans The Legion Condor: A History of the Luftwaffe in the Spanish Civil War pgs. 14-15
. The Legion Condor: A History of the Luftwaffe in the Spanish Civil War pgs. 25-27
 Laureau, Patrick Condor The Luftwaffe in
1936-1939 pgs 19-24 Spain
 Sperrle’s report to
1939-Legion Condor pg. 44