Emilio Mola y Vidal, posthumously created 1st Duke of Mola, (June 9, 1887 – June 3, 1937) was a Spanish Nationalist commander during the Spanish Civil War. Mola was actually the primary planner and leader of officers who initiated the coup that launched the war, whereas the official leader, José Sanjurjo, acted as a figurehead. When Sanjurjo was killed in a plane crash in the early days of the coup, Mola rose as the commander in the north. In October 1936, Mola launched a drive on Madrid with four columns of soldiers. He publically announced that a "fifth column" of Nationalists inside Madrid would help him take the city. The attack ultimately failed (but the phrase "fifth column" has entered into the vernacular).
Mola was killed in a plane crash himself in June 1937. Mola was succeeded as overall commander of nationalist forces by Francisco Franco. Naturally, the death of two leaders in plane crashes has cast suspicion on Franco, but there is absolutely no evidence that Franco had a hand in either man's death.
Hitler's War contains the only references to Mola in the series. As the Spanish Civil War follows the same broad course as it did in OTL until September 1938, even with Sanjurjo's presence, it is likely, but by no means certain, that Mola died under the same circumstances as OTL.