Operation ISTRIEN (1943)

Operation ISTRIEN

(Unternehmen Istrien / Operation Istria / Operacija Istra)

Intro

Operation goal was to occupy Slovenian littoral, Istrian peninsula, part of Kvarner littoral as well as Gorski Kotar to Ogulin in order to link up with Army Group F. Often confused with operation WOLKENBRUCH which followed immediately after probably beacuse they are locally known as Rommel's offensive (Romelova ofanziva) or October offensive..

History

After capitulation of Italy in September 1943 open uprising begun in Slovenian littoral, Istria, Croatian Littoral, Gorski Kotar, Notranjsko and Dolenjsko with disarming of the Italian units and formation of large liberated territory and several new Partisan brigades as well as 18th, 30th and 31st Slovenian division of NOVJ. German communication line between Italy and Sava valley was cut or severally disrupted.

German 194th Grenadier Regiment managed to secure major ports of Trieste, Pula (Pola) on 13 September and Rijeka (Fiume) and SuÅ¡ak on 15 September before Partisans could move in, but both Pula and Rijeka become effectively surrounded with neither side able to do anything.

On 19 September German High command give order to commander of Army Group B, Field-Marshal Erwin Rommel to suppress uprising and eliminate NOV i POJ forces in Gorski Kotar, east Slovenia, Slovenian littoral, Istra, Croatian Littoral and secure Adriatic coast in that area.

Task was given to 2. SS Panzer Corps under Paul Hausser which massed huge force for the operation over 40000 soldiers, 95 tanks, 41 assault guns, 23 tank hunters, 6 heavy self-propelled guns and around 300 half-tracks versus around 15000 Partisans.

Such massive superiority in armor allowed Germans to quickly achieve their goals against Partisans who had only few captured Italian tankettes and anti-tank guns which makes entire operation waste of resources at the time when Germany was hard pressed on Eastern front and in southern Italy.

Operation was divided into three phases.

Phase I - 25 September to 30 September

Taking control of Slovenian littoral.

2nd SS Panzer Corps managed to secure Trieste - Tolmin - Idrija - Postojna area as planed.

Phase II - 2 October to 7 October

Taking control of Istria and blocking any escape routes leading towards Gorski Kotar and Kvarner littoral. Germans prepared 30000 soldiers with 106 tanks and 295 half-tracks for this phase.

Task was given to 44th (132nd Regiment reinforced with 1st SS Grenadier Regiment, 21st Panzer Regiment) and 71st Infantry Division (194th Regiment reinforced with 901st Regiment) which took their starting positions on 1 October destroying Partisan Trieste battalion which happened to be in the area.

Lacking experienced officers Partisan HQ for Istria already decided to withdraw most of its 12000 soldiers (largely volunteers raised in past 10 days) to Gorski Kotar but escape route was cut before this could be done.

Germans achieved most of the planned objectives after only 2 days.

Phase III - 7 October to 20 October

Clearing of Istrian peninsula, Kvarner littoral and advance through Gorski Kotar to link up with Army Group B at Ogulin.

Because Phase II was completed quicker then planed preparations for Phase III were completed already on 6 October. Partisan General Staff of Croatia failed to react to this German concentration until it was to late sending orders for regrouping on 7 October after German attack already begun.

Casualties

German reports claimed Partisans suffered 4096 dead and 6850 captured, also taken were 32 artillery pieces and 2182 infantry weapons. Later estimates suggest Partisans and civilian death toll at around 2000 with further 500-600 sent to concentration camps.

Order of Battle

Aftermath

Operation become infamous amongst local population for indiscriminate killings of civilians and burning of entire villages in order to pacify the area through fear.

One of the primary goals of the operation railroad Rijeka-Delnice-Ogulin-Karlovac was found to be so severely damaged that it was considered unusable which made Germans lose interests in the area.

Reference

Zapadna Hrvatska u Drugom svjetskom ratu