The '1^st Iassy-Kishinev Offensive Operation', otherwise known as the 'Iassy-Kishinev Operation', was a Soviet undertaking named after the two major cities of Iassy and Kishinev (Iași and Chișinău in Romanian) in the area marking the start of the Soviet invasion of Romania (8 April/6 June 1944).

The offensive was the co-ordinated Soviet invasion of north-eastern Romania from Ukraine by General Polkovnik Ivan S. Konev’s 2^nd Ukrainian Front and General Rodion Ya. Malinovsky’s 3^rd Ukrainian Front in accordance with Iosif Stalin’s strategy of extending Soviet military power and political influence into the Balkans.

According to the Stavka’s plans, the two Soviet fronts were to cut through vital Axis defensive lines in northern Romania, thereby facilitating a subsequent Soviet advance into the entire Balkan region. The Soviet attack began with the 1^st Battle of Târgu Frumos and the Battle of Podu Iloaiei, and ended with the 2^nd Battle of Târgu Frumos. The Soviet forces failed to overcome the German defences in the region, and the offensive was ultimately a failure, largely as a result of the unexpectedly poor combat performance of the Soviet troops and the effectiveness of the German defensive preparations.

On 5 March 1944 Konev had started his 2^nd Ukrainian Front in the 'Uman-Botoşani Offensive Operation' in south-western Ukraine, and this undertaking succeeded by 17 March in its primary objective of splitting Generalfeldmarschall Erich von Manstein’s Heeresgruppe 'Süd' though the separation of Generaloberst Hans-Valentin Hube’s 1^st Panzerarmee and General Otto Wöhler’s 8^th Army, and by a time early in April Soviet formations were approaching the Soviet/Romanian border area.

Early in April, the Stavka ordered the 2^nd Ukrainian Front and 3^rd Ukrainian Front to undertake a major offensive with strategic implications into western Romania. The Stavka‍ '​s strategic objectives were to break German and Romanian strategic defences in north-eastern Romania, capture the key cities of Iași and Chișinău, and drive their forces deep into Romanian territory, if possible as far as Ploiești and Bucharest. By 5 April the 2^nd Ukrainian Front had crossed the upper reaches of Dniestr and Prut rivers, captured Khotyn and Dorohoi, and approached the areas of Târgu Frumos and Botoşani, some 30 to 60 miles (50 to 100 km) to the north-west of Iași, in the face of only light Romanian resistance.

On 8 April, Konev ordered General Leytenant Sergei G. Trofimenko’s 27^th Army and General Leytenant Filipp F. Zmachenko’s 40^th Army to undertale a co-ordinated offensive to the south along the axis to Târgu Frumos in close co-operation with General Polkovnik Semyon I. Bogdanov’s 2^nd Tank Army. While Konev’s shock group was advancing toward Târgu Frumos, General Leytenant Konstantin A. Koroteyev’s 52^nd Army and elements of General Leytenant Andrei G. Gravchenko’s 6^th Tank Army, which were operating in the area to the north of Iași, were undertaking operations in parallel with the Iași axis in order to support Konev’s main effort.

As Konev’s armies prepared to launch their offensive toward Târgu Frumos, Wöhler’s 8^th Army was involved in heavy fighting in and around the village of Popricani, some 9 miles (14.5 km) to the north of Iași, where two Soviet corps were fighting with armoured Kampfgruppen, in the process distracting the Germans' attention and forces away from the critical Târgu Frumos sector. Exploiting the 52^nd Army’s diversionary operations in the Iași region, the three armies of Konev’s shock group began their advance to the south early in the morning of 8 April. The advance was relatively slow as a result of the mud-clogged nature of the roads during the rasputitsa thaw and rain, as well as the crossing to the western bank of the Prut river to the north-west of Iași.

The initial task of Konev’s armies was to reach the Târgu Frumos, Pașcani and Târgu Neamț areas some 30 to 60 miles (50 to 100 km) to the west of Iași, and to surprise the Romanian defence and thus capture the three towns. While three divisions of General Major Piore P. Avdeyenko’s LI Corps were ordered to press forward to the south in the direction of Pașcani, another two divisions shielded their advance in the region to the north and north-west of Târgu Neamţ. Farther to the east, seven divisions assigned to General Leytenant Sergei G. Goriachev’s XXXV Guards Corps and General Major Aleksei I. Semenov’s XXXIII Corps of the 27^th Army were to advance to the south-east along the Prut river, starting on 7 April, forcing General de divizie Dumitru Carlaont’s Romanian 8^th Division to retreat toward Hârlău, some 17 miles (27 km) to the north of Târgu Frumos. Meanwhile another two divisions of the XXXIII Corps, supplemented by two corps of the 2^nd Tank Army, were to press General de brigadâ Agricola Filip’s Romanian 7^th Division back toward Târgu Frumos.

The IV Corps of General de corp de armatâ Mihai Racoviță's Romanian 4^th Army, which was commanded by General de divisie Nicolae Stoenescu and responsible for defending the Târgu Frumos sector, was preparing to group a strength sufficient to man and hold the forward defensive positions along the defensive line linking Ruginoasa, Strunga and Oţeleni, which extended from Târgu Neamţ to the east from a point to the south of Pașcani and through Târgu Frumos and Podu Iloaiei just to the south of Iași. As a result, General de brigadâ Gheorghe R. Gheorghiu’s Romanian 6^th Division and Carleont’s 8^th Division would be manning defences extending from Târgu Neamţ to the east as far as Pașcani, while General de divisie Radu Niculescu-Cociu’s 1^st Guards Division and Filip’s 7^th Division would defend the sector from Pașcani to the east past Târgu Frumos to Podu Iloaiei. The latter units would be reinforced by the end of 8 April, at a location 9 miles (14 km) to the north-east of Podu Iloaiei by a small Kampfgruppe of von Edelsheim’s 24^th Panzerdivision.

Heading Trofimenko’s 27^th Army, Goriachev’s XXXV Guards Corps resumed its advance to the south from the area of Hârlǎu in the direction of Târgu Frumos during the morning on 9 April, with two infantry divisions deployed side-by-side in his first echelon. The Soviet infantry soon bested the Romanian troops defending the town and most of the surrounding region, being reinforced by the corps' second echelon, comprising single airborne and infantry divisions, before there was any Axis reaction. Meanwhile, the 42^nd Guards Division captured the town of Pașcani, some 14 miles (23 km) to the west of Târgu Frumos and defended by the Romanian 6^th Division. At the same time, forward detachments of Bogdanov’s 2^nd Tank Army, advancing to the east of the town, attempted to reinforce Trofimenko’s infantry fighting in the Târgu Frumos region, but were prevented from doing so by the presence of German defenders. The German 8^th Army was reacting promptly as it perceived the threat to its main defences in the area to the west of Iași, moving Generalleutnant Hasso-Eccard von Manteuffel’s Panzergrenadierdivision 'Grossdeutschland' toward Târgu Frumos. Elements of the division were ordered to launch a counterattack from the south of the town as soon as possible. Attacking during the rest of the day, that small German force managed to seize and hold only a foothold in the southern part of the town.

By this time, however, two divisions of Goriachev’s XXXV Guards Corps had reached the region and added their weight to Trofimenko’s advance to the south. By the fall of night, the three divisions leading the advance of the XXXV Guards Corps had passed Târgu Frumos and created a salient 3 to 7 miles (4.8 to 11.25 km) deep within the Romanian defence line to the south and south-east of the town.

Early on 10 April, the Panzergrenadierdivision 'Grossdeutschland', with some 160 tanks including 40 Panther battle and 40 Tiger heavy machines, attacked to the west along the road from Podu Iloaiei to Târgu Frumos in two columns deployed to the north and south of the road. Following a heavy artillery bombardment, the Germans broke into the town and engaged the Soviets, who had taken cover in many of the town’s buildings. The German thrust isolated several Soviet units from their main force and reached the high ground to the west of the town by launching a concerted counterattack just as the 206^th Division, 3^rd Guards Airborne Division and 93^rd Guards Division were readying themselves for a resumed assault to the south, at a time when only their rearguards and logistics units remained to defend the Târgu Frumos region.

The Romanian 1^st Guards Division and 7^th Division meanwhile advanced from the south, pressing the Soviets back to the north. Trapped between the German armour pressing into Târgu Frumos from the east and the Romanian infantry counterattacking from the south, the XXXV Guards Corps' three divisions had little option but to fall back, and at about 22.00, 48 hours after getting their original order, the Panzergrenadiers had secured Târgu Frumos and the areas lying to the west and north of the town.

After a desperate two-day struggle as the three divisions of the XXXV Guards Corps attempted to avoid encirclement, the fighting in the Târgu Frumos area drew to a close by 12.00 on 12 April.

Following the end of the battle, the Panzergrenadierdivision 'Grossdeutschland constructed a new line for the defence of Târgu Frumos: this extended in a wide arc from 5 miles (8 km) to the north-west, 6 miles (10 km) to the north-east and 9 miles (14 km) to the east of the town. von Manteuffel ultimately placed his formation’s Grenadierregiment 'Grossdeutschland' on the division’s left wing to the north-west of the town and its Füsilierregiment 'Grossdeutschland' on its right wing to the north-east and east of the town, and retained the Panzerregiment 'Grossdeutschland' in reserve close to Târgu Frumos proper.

Meanwhile, units of the Grenadierregiment 'Grossdeutschland' cleared remnants of the 206^th Division and 3^rd Guards Airborne Division from a small Soviet pocket to the west of the town throughout 12 April, and extended the regiment’s defensive positions several miles forward to the south-west of Heleşteni, itself 7 miles (11.25 km) to the west of Târgu Frumos, to connect the defences of the Panzergrenadierdivision 'Grossdeutschland' with those of the Romanian 1^st Guard Division and thus create a continuous defensive front to the west of the town. Furthermore, on the right flank of the Panzergrenadierdivision 'Grossdeutschland', a Kampfgruppe from the 24^th Panzerdivision continued defending the sector located from north of Podu Iloaiei to the village of Leţcani, 10 miles (16 km) to the west of Iași, where its right flank linked with the defences of the Romanian 7^th Division, which was defending the north-western flank of Iași.

After successfully withdrawing the three partially encircled divisions of the XXXV Guards Corps, Trofimenko reorganised the defences of his 27^th Army along a line extending from a point to the north of Târgu Frumos eastward to a location to the north of Podu Iloaiei. By the end of 12 April, Goriachev deployed the 206^th Division, 3^rd Guards Division and 93^rd Division from left to right in defensive positions stretching from the eastern bank of Siret river near Pașcani, 15 miles (24 km) to the west of Târgu Frumos, eastward to the village of Munteni, 10 miles (16 km) to the north-east of Târgu Frumos, while farther to the east, three divisions of the XXXIII Corps were sited 9 miles (14 km) to the north-west of Iași.

Irritated by the defeat of his forces at Târgu Frumos, on 12 April Konev ordered Bogdanov, whose 2^nd Tank Army concentrated its two corps to the south of Focuri, 10 miles (16 km) to the north of Podu Iloaiei, to assault the German defenders at Podu Iloaiei. The resulted in the Battle of Podu Iloaiei. The battle was an armoured engagement near Scobalteni, where with German support General de brigadâ Radu Korne’s 1^st Rumania Mare Armoured Division held off the Soviet armour of two tank corps and two infantry divisions for a single day: the battle cost the Germans and Romanians 250 and 100 casualties respectively, and the Soviets 5,400 men killed and 1,800 taken prisoner (1,100 by the Romanians and 700 by the Germans) as well as 124 tanks (97 and 27 knocked out by the Romanians and Germans respectively). At the end of the battle, the Germans managed to drive the Soviets back to the positions they had held before the battle.

The fighting round Târgu Frumos was resumed, after a three-week lull, between 2 and 8 May in the 2^nd Battle of Târgu Frumos, which took the form of a series of engagements and smaller combats over several days in which armoured forces of General Friedrich Kirchner’s LVII Panzerkorps, more specifically the Panzergrenadierdivision 'Grossdeutschland' and the 24^th Panzerdivision, engaged General Major Ivan V. Dubuvoi’s XVI Tank Corps of the 2^nd Tank Army, which had resumed its attack from the north.

Despite initial successes by the Soviets, a series of counterattacks managed to halt the Soviet offensive, and the battle reduced Soviet tank strength to a point where a continued attack into Romania was not possible. In the three days of fighting, the LVII Panzerkorps and General Erich Buschenhagen’s LII Corps defeated the Soviet force and claimed the destruction of more than 350 Soviet tanks, about 100 of these by the 24^th Panzerdivision.

At the end of the 2^nd Battle of Târgu Frumos, which was the result of a Soviet local effort to improve its current positions rather than a fully fledged offensive, the front line had stabilised by 6 June. It is worth noting, however, it was from these positions that the Soviets then launched their strategically decisive '2^nd Iassy-Kishinev Strategic Offensive Operation' in the later part of August.

On a political level, the '1^st Iassy-Kishinev Offensive Operation' accelerated the activities of anti-German sentiment in Romania, leading to negotiations between the traditional political parties and the Romanian communist party, and this paved the way toward Romania’s armistice with the Soviets and then the country’s change of sides in the '2^nd Iassy-Kishinev Strategic Offensive Operation'.