[8] In order to do this, Tito formed the so-called Main Operational Group, which eventually succeeded in forcing its way across the Neretva in mid-March 1943, after a series of battles with various hostile formations.

Other Partisan formations, the 1st Croatian and 1st Bosnian Corps, managed to evade Axis blows and, despite significant losses, reclaim most of the territory they had held before the beginning of the operation.

In such an event, resistance forces in Yugoslavia would be likely to interfere with German defensive operations as well as their economic exploitation of natural resources, including timber, copper and bauxite.

As a result, on 16 December 1942 Adolf Hitler ordered the Armed Forces Commander in Southeast Europe, Generaloberst Alexander Löhr, to crush the resistance in Yugoslavia.

On 2 January Draža Mihailović reported his plan to the Chetniks for the destruction of the Partisans' Bihać Republic in order to "liberate this Serb territory from Communist terror".

[15] According to the plan, four German divisions (7th SS Volunteer Mountain, 369th, 714th and 717th) were to attack from the arc stretching from Karlovac across Glina, Kostajnica, Bosanski Novi and Sanski Most towards the line Bihać--Petrovac.

According to the plan, the 7th SS and 717th Divisions, deployed on the extreme ends of the arc, were to race into the enemy rear with motorized battle groups and meet at Vrtoče on the second day of the operation.

Over the following days both sides stepped up their efforts, building up strength at the key point; the Partisans remained successful in blocking German attacks, while launching fierce night counterattacks.

[24] The 369th Division and the 3rd Home Guard Mountain Brigade, facing only Partisan rearguards, reached Bosanska Krupa on 30 January and relieved the encircled 737th Regiment at Benakovac a few days later.

The original idea was to start the large movement in the spring, but signs of an imminent Axis offensive in January 1943 made Tito order the commencement of the operation without delay.

The main Partisan force was divided into three columns: 7th Banija Division was tasked with acting as the group's rearguard and protecting the recently formed "Central Hospital" with some 4,000 sick and wounded.

The 1st Battalion of the 260th Regiment of the Division Murge intervened from Mostar, but was almost completely annihilated (120 dead and 286 captured, including the Commander, Lt. Col. Francesco Metella), on 16 February with the loss of all its equipment.

The offensive continued with the 10th Herzegovina Brigade of the 3rd Partisan Division attacking and routing a company from the 1st Battalion of the 259th Regiment in Rama on 20 February, inflicting losses of 183 killed and 7 captured Italian soldiers.

Colonel Malantonio was shot after the Partisans had determined that he was a prominent member of the Fascist Party, and that he had taken part in the Spanish Civil War as an officer in the Italian Corpo Truppe Volontarie.

[37][38] With the fall of Jablanica, Partisans were in control of the entire Neretva valley between Mostar and Ivan Sedlo; only the strategically important town of Konjic was still in Italian hands.

Worst of all, the Partisans captured Posušje and endangered the wider Mostar area, which provided the German war industry with 10 percent of its bauxite ore needs.

After regrouping, the Partisans reclaimed their positions on the Ivan sedlo on the next day, but a substantial part of the battle group, including one German and one Home Guard battalion, an Ustaša company, and a number of tanks, succeeded in breaking through to Konjic on 22 February.

[24] As the blockade of the Ivan Sedlo Pass by the 1st Proletarian Division seemed to be holding, and no further parts of the battle group Annaker reached Konjic, Tito decided to send another brigade.

The appearance of the 717th Infantry Division (now attacking Prozor instead of Livno, as originally envisaged by the plan for Weiss 2) on the flank of battle group Vogel endangered the whole western front of the NOVJ; the Central Hospital at Šćit was now directly exposed to the German onslaught.

The division, deployed in the broader area of Imotski, was already under pressure from the east (Italian regimental battle group "Scotti" from Mostar) and the south-east (Montenegro Chetniks under Vesković from Ljubuški).

In the fight on 4 March the 2nd Proletarian Brigade captured Major Strecker, Commander of the 3rd Battalion of the 738th Regiment, and in the following days used him to propose a prisoner exchange and talks on some other subjects to the Germans.

On the assumption that the Partisans would continue their advance towards Bugojno, General Lüters ordered the 369th Division to the area on 6 March, noting in the War diary that "the key error (was) G.Vakuf".

After the counter-attack had been launched, the brigade commander Ljubo Vučković did not consider the possibility of return to the river, and consequently ordered the evacuation of Jablanica, deploying his unit on the hills outside the town.

Under the cover of darkness, one group of 12 men from the 2nd Company of the 3rd Battalion of the 2nd Dalmatian crossed the skeleton of the railway bridge and began climbing up the steep eastern bank.

On 5 March, the commander of the 3rd Partisan Division, Pero Ćetković [sh], received an order to push the Germans back to the town, and seal-off the garrison for good.

When air reconnaissance brought this information to the German command, they concluded that the Partisans must be preparing a final dash north of their current position (along the western shore of the Neretva), and had blown up the bridge to prevent desertion as well as attack by Chetnik forces from the other side of the river.

With their rearguard fighting off an increasingly powerful German advance, the Partisans crossed the river under intense aerial bombardment (the Axis deployed large Luftwaffe formations), but the mountainous landscape prevented accurate destruction of the makeshift bridge.

The humiliating strategic defeat was amplified by Tito being able to keep his well-known pledge not to leave the wounded behind, as they faced certain execution at the hands of the Axis (which later actually happened in the aftermath of the Battle of the Sutjeska).

In fact, once they reached the eastern parts of Bosnia and Herzegovina, the Partisans had to face only the Chetniks, and in turn almost entirely incapacitated them in the area west of the Drina river.

Alistair MacLean's 1968 thriller novel Force 10 From Navarone, subsequently filmed, also brings forth the fight of outnumbered Partisans against Germans and Chetniks, and the blowing up of the Neretva bridge.