Ernst Ludwig Ferdinand von Delius was the second of three sons of Dr. Ing. Hc Friedrich von Delius and Katharina Schwenke. He was a great-great-grandson of Daniel Heinrich Delius, a Prussian district president. His family came from the County of Ravensberg (present day Westphalia) and he grew up in the southern Brandenburg town of Plessa, where his father was the owner of the local coal mine. In 1924 he designed and built the very first overburden bridge for the removal of soil and rock that covered the mineral deposits. This revolutionised the extraction of Lignite (brown coal).
He started driving at an early age driving a DKW to school when he was 15. A career in engineering was planned but Ernst had other ideas and turned to motor racing, entering his first race in August 1931 at AVUS finishing 6th in a sports car race. In the following years he achieved a series of successes in a variety of competitions and established a competitive reputation.
He raced a Zoller in 1934. The Zoller was a 1500 cc Voiturette with 2-stroke twin supercharged 12 cylinder motor! Sadly it reliability and the untimely death of Arnold Zoller brought to an end any prospect of developing the car and engine further. In 1935 he raced the Zoller and an ERA.
On the advice of Ferdinand Porsche, Auto Union took him on in 1936 as a junior driver. Driving alongside Bernd Rosemeyer and Hans Stuck, Ernst was able to hold his own, finishing 2nd in the Coppa Acerbo at Pescara behind Bernd Rosemeyer but ahead of Achille Varzi. He also had a third in the Italian Grand Prix at Monza.
In January 1937 he won the Grosvenor GP handicap race in Cape Town, South Africa from Rosemeyer (Auto Union) and Howe (ERA) in a handicap race where the Auto Union drivers caught Howe on the last lap. In May he took third in the Tripoli Grand Prix at the Autodromo di Mellaha and followed that with second at the Grand Prix at Avus. Things were going well and, early in July, a 4th in the Vanderbilt Cup (which was won by his team mate Bernd Rosemeyer) added to his blossoming reputation however 20 days later having returned to Europe for the German Grand Prix, tragedy struck.
On lap 6 as von Delius attempted to pass Richard Seaman's Mercedes W125 on the long Antoniusbuche straight at 250 kph he brushed the hedge and then collided with the Mercedes. Seaman hit the kilometer marker post braking his nose and thumb while Ernst went through the hedge into a field and ending up on the road outside the circuit. Von Delius broke a leg and other injuries and was transported to hospital in Bonn. Though initially his injuries were not thought to be life threatening, overnight his condition worsened and his died the following day suffering from thrombosis and other complications.
In his memory a road in his home town of Plessa was renamed the Von Delius Straße and a memorial to him was inaugurated in July 2002.