
The Luftwaffe had a shortcoming in the lack of an efficient heavy bomber fleet. Generalleutnant Walther Wever, the Luftwaffe's first Chief of Staff, was the most persistent advocate of a German long-range strategic bomber fleet. It was built for the Luftwaffe's Ural bomber program under General Wever, competing against the Junkers Ju 89. The RLM Technisches Amt issued a specification for a four-engine heavy bomber. But after Wever's death in an airplane crash in June 1936, Wever's successor, Albert Kesselring, canceled Germany's long-range bomber projects to concentrate on tactical bombers.
Both Dornier and Junkers were competitors for the contract, and each received an order for three prototypes in late 1935. The Dornier design was given the project number Do 19, while the Junkers prototype became the Ju 89.

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Brown, Eric, Captain - Wings of the Luftwaffe
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Wikipedia - Dornier Do 19