This was a Soviet amphibious operation within the ‘Baltic Offensive Operation’ and designed to clear the forces of Generalfeldmarschall Ferdinand Schörner’s Heeresgruppe ‘Nord’ from the islands of the Moonzund archipelago in the Gulf of Riga (29 September/24 November 1944).
Formally known as the ‘Moonzund Landing Operation’ and partnered by the 'Riga Offensive Operation' (14 September/24 October), 'Tallinn Offensive Operation' (17/26 September) and 'Memel Offensive Operation' (27 September/24 November), the attack was entrusted to General Leytenant Filipp N. Starikov’s 8th Army of Marshal Sovetskogo Soyuza Leonid A. Govorov’s Leningrad Front. Occupying a key location in the mouth of the Gulf of Riga, these Estonian islands were defended largely by units of Generalleutnant Hans Schirmer’s 23rd Division, which had been split across the three islands and reinforced with a variety of artillery, coastal artillery, and assault engineer detachments.
The islands of Saaremaa, Hiiumaa and Muhu (Ösel, Dagö and Moon in German) are the largest islands in the archipelago off the north-west coast of Estonia, and dominate the sea lanes to Helsinki, Leningrad (now St Petersburg) and Tallinn (Reval in German), as well as the Gulf of Riga itself. The islands are almost completely flat, the highest point rising only to some 65 ft (20 m) above sea level. Most of the islands are covered in woods, and marshes and fields also dominate the landscape. Much of the surrounding Baltic sea is shallow, making it unsuitable for the operation of major vessels.
The Soviet forces assigned to the attack were General Leytenant Lembit Pärn’s Estonian VIII Corps and General Leytenant Ivan P. Alferov’s CIX Corps, which were ordered into action on 29 September 1944. The troops were transported to the first beach-head at Kuivastu on Muhu island using Lend-Lease landing craft, including DUKW amphibious trucks supplied by the USA. Many of these troops were Estonians: some of these were genuine volunteers, but most had been forcibly conscripted into the ranks of the advancing Soviet army, as was usual as the Soviet forces recaptured or, in this instance, re-invaded lost territories. While boosting the units’ combat strength on paper, this influx of untrained and often unwilling civilians into military units often left something to be desired in terms of combat capability.
The Germans’ first response to the landing was to withdraw their garrison on Muhu, after weak initial resistance, before destroying the causeway between Muhu and Saaremaa; they also withdrew their forces on Hiiumaa to Saaremaa, where they landed Generalleutnant Viktor Lang’s 218th Division and Generalmajor Gottfried Weber’s 12th Felddivision (L) as further reinforcement.
The Soviet plan had originally envisaged clearing the archipelago by a date no later than 5 October, but adverse weather and German resistance greater than had been anticipated interfered with their advance. However, after securing Hiiumaa, Soviet forces eventually landed between Jaani and Keskvere in the north of Saaremaa during 5 October. In an almost exact reversal of the roles from the German ‘Beowulf’ invasion in 1941, this time it was the weak German forces which traded space for time, withdrawing across the island and making occasional stands before the numerically superior Soviet forces.
The German plan was to make a final stand at the narrow, more easily defendable Sõrve peninsula (Halbinsel Sworbe in German) on the south-western side of Saaremaa. Several sharp engagements took place, most notably the Battle of Tehumardi, but by 8 October all that was left of the German forces had been forced back to the Sõrve peninsula. The rest of the island, including the town of Kuressaare (Arensburg in German), was now in the hands of the Soviets, who now reinforced their attacking forces with the XXX Guards Corps.
Despite their major numerical advantage in armour, artillery and infantry, as well as air superiority, the Soviets found that their attacks failed to make any initial progress. The Germans had constructed solid defensive positions, built upon remnants of the Soviet 1941 positions. To provide an observation platform in the flat terrain, the Soviets used two tethered observation balloons, and from these observers were able to direct artillery fire against German positions and supply columns. The Soviets tried more amphibious attacks, in this instance behind the German lines, but these were repulsed with heavy losses.
A few days before the end of the battle, the Germans received effective naval gunfire support from warships including the heavy cruisers Admiral Scheer (ex-pocket battleship) and Prinz Eugen. The warships’ guns were accurate and hard-hitting, but it was now a matter of support which was too little and too late. The Soviets also had naval support, and there were several minor clashes between the German and Soviet naval forces. Eventually, after several weeks of bitter fighting, the Germans were at the end of their tether after endless attacks and ceaseless artillery fire. They had lost their most powerful combat formation when the 12th Felddivision (L) was pulled back to Kurland, on the southern shore of the Gulf of Riga on 12 November, and no more replacements were forthcoming, forcing them back on successive defensive lines. Because of the marshy nature of the terrain and the low water table, it was often difficult to prepare proper defensive positions.
By 23 November the German defences had become untenable, and Schörner gave the order to evacuate. This was contrary to an explicit order by Adolf Hitler to defend the island to the last man, but Schörner got away with this disobedience. By the early hours of 24 November all of the surviving defenders had been shipped out to Ventspils (Windau in German) on the embattled Kurland peninsula by a naval force under the command of Generalmajor Karl Henke. The surviving members of the defending forces numbered about 4,500 men including 700 wounded, representing only some 25% of the original defending force. Previous casualties had been evacuated at earlier times, together with Soviet prisoners and a large number of Estonian civilians not wanting to pass into Soviet rule once again. All the remaining guns and vehicles were destroyed, and 1,400 horses were shot. The few Germans who did not reach the coast in time to be evacuated were killed by the Soviet forces.