In the final hours of Nazi Germany, Adolf Hitler
named an unlikely successor: Grand Admiral Karl Dönitz.

For 20 critical days in May 1945, a naval
officer, not a general or party official, held the highest office in a defeated regime, navigating
surrender as millions fled the advancing front.

Karl Dönitz was born on 16 September 1891 in Grünau, a quiet district near Berlin.

His
family belonged to Germany’s growing middle class, and like many young men of the era, he chose a
military career path.

In April 1910, he entered the Imperial German Navy, a force still expanding
its reach under Kaiser Wilhelm II.

Dönitz completed officer training and soon received his
first major assignment aboard the light cruiser SMS Breslau, then stationed in the Mediterranean.

By 1914, when the First World War began, the Breslau and its partner ship Goeben were
already at sea.

Their escape to Constantinople and subsequent transfer to the Ottoman Navy
became one of the most notable naval maneuvers of the war’s opening days.

For Dönitz, this
period offered experience in high-pressure operations and complex diplomacy.

But his real
shift came in 1916, when he transferred to Germany’s growing U-boat service, a branch that
demanded technical skill and absolute composure.

In January 1918, Dönitz received command
of UB-68, a coastal submarine operating in the Mediterranean.

His time as a commander
was short but intense.

On 4 October 1918, after mechanical failures left the boat unable
to dive, UB-68 was forced to surface under fire from British warships.

Dönitz ordered his crew
to abandon ship before the submarine sank.

He was taken prisoner and spent the rest of the
war in a British POW camp.

During this period, he wrote detailed notes on submarine tactics,
early ideas that would later influence the concepts he introduced in the next war.

Released in July 1919, Dönitz returned to a shattered Germany.

The Reichsmarine, the navy
of the Weimar Republic, had been reduced to a fraction of its former strength by the Treaty of
Versailles.

He held several staff and training roles during the 1920s, focusing on gunnery,
signals, and ship operations.

Although submarines were banned under Versailles, the German navy
continued to explore them covertly through partnerships and research abroad.

Officers like
Dönitz remained quietly connected to the concepts even when official programs did not exist.

By the early 1930s, Dönitz had become a respected figure within the Reichsmarine,
known for discipline, technical skill, and an interest in submarine operations even
when official programs were forbidden.

As Germany began to rearm under Hitler, the navy looked for
officers who could lead a rebuilt U-boat force.

When Karl Dönitz became Commander of the Submarines, he inherited a small submarine
arm that was still rebuilding after years of restrictions.

Germany possessed
only a handful of operational U-boats, but Dönitz had a clear vision: a modern submarine
fleet built around coordination, discipline, and concentrated attack.

He believed Germany needed
at least 300 submarines to wage an effective naval campaign, far more than political leaders
or industrial planners were prepared to deliver.

Dönitz’s most influential contribution
was the development of Rudeltaktik, or wolf-pack tactics.

Instead of operating
alone, submarines would patrol across wide areas, report convoy sightings, and then regroup for
coordinated night attacks.

This demanded constant radio communication and rapid decision-making from
command headquarters.

It also required a large enough fleet to sustain losses while maintaining
pressure across the Atlantic.

Dönitz built his doctrine around speed, surprise, and centralized
control, principles that later defined the first years of the Battle of the Atlantic.

When war began on 1 September 1939, Germany had only 57 U-boats, with fewer than
half ready for long-range operations.

Despite the limited numbers, early successes gave Dönitz
influence within the naval leadership.

U-boat crews operated from traditional bases
in Wilhelmshaven, Kiel, and Helgoland, but the fall of France in June 1940 transformed
the campaign.

German forces captured Atlantic ports such as Lorient, Brest, La Rochelle, and St.

Nazaire, allowing U-boats to reach the open ocean within hours instead of days.

These bases became
central to the U-boat war, protected by reinforced submarine pens built to withstand bombing.

Dönitz rose quickly through the ranks.

He became Rear Admiral in 1939, Vice Admiral in
1940, and Admiral in 1942.

In January 1943, after disagreements between Hitler and the
long-serving naval commander Erich Raeder, Dönitz replaced him as Commander-in-Chief of
the Kriegsmarine.

The appointment reflected both Hitler’s trust in him and the growing
importance Hitler placed on submarine warfare.

By 1941 and 1942, the U-boat arm reached
what crews called the “Happy Time,” when convoys lacked adequate escort protection.

But the situation changed rapidly in 1943.

Advances in Allied radar systems, the breaking of
German naval codes, improved air patrols, and new escort carriers dramatically increased losses.

Germany lost more than 70 U-boats in May 1943 alone, a level of attrition that forced Dönitz
to withdraw many boats from the North Atlantic.

Despite these setbacks, Dönitz maintained
a close relationship with Hitler, often briefing him directly.

He became one of the
few senior officers who retained the Führer’s confidence in the final years of the conflict.

His
loyalty and measured communication style stood in sharp contrast to the internal rivalries
that marked much of the Nazi leadership.

Although Dönitz later presented himself
as a non-political naval officer, his wartime record shows clear alignment with
Nazi ideology.

Several senior officers described him as strongly loyal to Hitler and supportive of
National Socialism, and he encouraged these views within the Kriegsmarine.

Dönitz joined the
Nazi Party in February 1944 and received the Golden Party Badge later that year.

His speeches
included explicit antisemitic language.

He also blamed foreign decisions on what he called
“international Jewish capital.

” After 1945, Dönitz denied political involvement and stated
he had no knowledge of the persecution of Jews, but his public statements during the
war reflect firm ideological commitment.

In the final days of April 1945, the Third Reich stood on the edge of
collapse.

Soviet forces surrounded Berlin, Allied troops pressed in from the west, and
German command structures were breaking down.

Inside the Führerbunker, Adolf Hitler drafted
his political testament on 29 April, naming Grand Admiral Karl Dönitz as Reichspräsident,
head of state, after his death.

Hitler chose him over senior party figures for reasons
that reflected the final state of the regime: Dönitz had remained loyal, avoided internal
disputes, and maintained one of the few military structures still functioning as Germany collapsed.

On 30 April 1945, Hitler died in Berlin.

The news reached Dönitz that evening at Plön, on the
Baltic coast.

His first reaction was disbelief, but once the message was confirmed, he
acted quickly.

He moved his headquarters north to the Naval Academy at Mürwik, near
Flensburg, where he could operate under the protection of remaining naval units.

There, he
formed the short-lived Flensburg Government, appointing Count Lutz Graf Schwerin von Krosigk as
“Leading Minister.

” Though nominally a government, it controlled almost no real territory and
operated under constant Allied observation.

Dönitz faced an impossible task: manage the final
defeat of Germany while trying to protect millions of civilians and soldiers still in the east.

His
overriding objective during these 20 days was to facilitate the movement of German refugees and
troops westward to surrender to the British or Americans rather than fall into Soviet hands.

On 4 May 1945, Dönitz authorized the partial surrender of German forces in Northwest
Germany, Denmark, and the Netherlands.

But this did not end the war.

Full capitulation
required coordinated action across all fronts, and Allied commanders made clear that only
an unconditional surrender would be accepted.

On 7 May, German representatives led by General
Alfred Jodl signed the surrender document at Reims, agreeing that all German forces would cease
operations on 8 May 1945.

Dönitz authorized this, realizing resistance was no longer possible.

A
second signing took place in Berlin-Karlshorst on 8–9 May, formalizing the act for the
Soviet Union.

The war in Europe was over.

Despite the surrender, Dönitz attempted to
keep his government functioning.

The Allies allowed it to operate for two more weeks,
mainly to maintain administrative stability in the occupied region around Flensburg.

But by late May, its presence was seen as unnecessary and politically unacceptable.

On 23 May 1945, British forces arrived at the Naval Academy in Mürwik.

Officers entered
the meeting room, informed Dönitz that his government was dissolved, and placed him
under arrest along with key ministers.

The last leader of Nazi Germany walked out of the
building without ceremony, ending the brief existence of the Flensburg Government.

After his arrest on 23 May 1945, Dönitz
was transferred into Allied custody and soon became one of the major defendants at the
International Military Tribunal in Nuremberg.

The charges against him covered two central
areas: responsibility for planning and waging aggressive war, and the conduct of the U-boat
campaign in violation of international law.

Prosecutors emphasized his loyalty to Hitler,
his leadership role within the Kriegsmarine, and several naval directives that
encouraged uncompromising tactics at sea.

One of the most scrutinized issues involved orders
concerning the rescue of enemy survivors.

In 1942, Dönitz had instructed submarine commanders to
avoid rescue operations in dangerous conditions.

Prosecutors claimed this encouraged unnecessary
loss of life, though Dönitz argued that surfacing exposed U-boats to air attack and that similar
practices had been adopted by other navies.

Testimony from U.

S.

Admiral Chester Nimitz, who
described comparable restrictions on American submarines, became a key factor.

It did not
absolve Dönitz but helped refine the tribunal’s judgment of his actions as part of broader
naval realities rather than intentional cruelty.

Nonetheless, the tribunal held him responsible for
participating in the Nazi leadership’s aggressive military policies.

Although acquitted of the
charge that he conducted unrestricted submarine warfare knowingly outside accepted norms, he
was found guilty on two counts and sentenced to 10 years in prison on 1 October 1946.

The court
noted his deep involvement in the Nazi war effort, even if his political influence had been
more limited than that of other defendants.

Dönitz served his full sentence at Spandau Prison
in Berlin, a facility jointly administered by the four occupying powers.

His time there
was marked by strict routines, limited contact with the outside world, and occasional
disagreements among the Allied administrators on prison policy.

Unlike some other inmates,
he rarely expressed regret for his wartime decisions.

He focused instead on maintaining a
disciplined daily structure, reading, writing, and corresponding within the limits allowed.

Upon his release on 1 October 1956, Dönitz settled in Aumühle, a quiet town in Schleswig-Holstein.

He returned to public attention two years later with the publication of his memoir, Zehn Jahre
und zwanzig Tage (“Ten Years and Twenty Days”).

The book presented his wartime role as that of
a dedicated naval officer focused on strategy rather than politics.

Supporters viewed him
as a symbol of professional military service, while critics argued that the memoir downplayed
his loyalty to Hitler and ignored the moral consequences of the regime he served.

Even after the Nuremberg Trials, when the crimes of the Nazi regime were well-known, Dönitz
continued to express antisemitic views.

In April 1953, he told Albert Speer that he believed he
would already have been released from prison “if it had been the choice of the Americans and not
the Jews.

” This remark made clear that his views had not changed, even in the years after the war.

Karl Dönitz died on 24 December 1980 at age 89.

His funeral drew several hundred former naval
personnel, but no official military honors were permitted, reflecting Allied concerns
about symbolism.

His legacy remains divided: a skilled naval strategist, a devoted officer,
and the final leader of a defeated regime If you enjoyed this video, watch “What
Happened to the German U-Boats After WW2?” next.

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