The Division was established at Kursk prior to June 1941. On 22 June 1941 it was part of 33rd Rifle Corps in the interior Orel Military District. Fighting as part of the 19th Army, it was wiped out at Vyazma in October 1941.
The division was re-formed in December 1941 in the capital of the Armenian SSR, Yerevan, following the German invasion of the Soviet Union. It was a redesignation of the 474th Rifle Division, which was formed on 14 December 1941 and renumbered the 89th Rifle Division on 26 December 1941. Over the course of the war period, the division had a number of commanders, including Colonel Simeon G. Zakyan (who was killed in action in April 1942 during military operations in the Kerch peninsula), Lieutenant-Colonel Andranik Sargsyan, Colonel Artashes Vasilyan, and finally Colonel Nver G. Safaryan, who took over command in February 1943 and would eventually attain the rank of Major General. It published its own weekly Armenian-language newspaper called the Red Soldier (Կարմիր Զինվոր).
In August 1942, the 89th Division was dispatched toward the North Caucasus Front, where it took up defensive positions to block the German drive toward Grozny. From November to December 1942, the unit took part in several fierce battles in the area around the cities of Elekhotvo, Malgobek, and Voznesenskaya and helped bring the German penetration into the Caucasus to a halt. As the Soviet armies shifted to the offensive during the winter of 1942-43, the 89th Division began its gradual advance toward the Crimea. On January 21, 1943, along with other Soviet forces from the Transcaucasian Front, it participated in the capture of Malgobek, Khamedan and a number of other settlements previously held by the Germans. The unit's advance picked up pace in the following month, averaging about 30-40 kilometers a day as it approached the Sea of Azov.
The Germans put up a stiff resistance in the Crimea, and in the fighting around the settlement of Novo Jerilka division commander Colonel Vasilyan was killed. The 89th itself suffered heavy casualties but in the following months fresh recruits from Armenia brought it back to full strength, and Vasilyan's successor and the division commander was the able Colonel Nver Safaryan. In September 1943, the division was redeployed and ordered to attack the Axis defensive fortifications on the Taman Peninsula. On September 6, it moved in a northeasterly direction from Novorossiysk and engaged in heavy fighting for several days until the Axis defenses were overwhelmed and the villages of Verkhnebakansk and Taman were liberated on September 18 and October 3, respectively. The 89th distinguished itself in these two battles and was given the honorary title of "Tamanskaya" (Таманская; Tamanyan, Թամանյան)." Two soldiers from the division in particular, Senior Sergeants Hunan M. Avetisyan and Suren S. Arakelyan, were noted for the courage they displayed during the fighting and were both posthumously awarded with the medal of the Hero of the Soviet Union.
On November 21, the 89th Division participated in the Kerch–Eltigen Operation, an ambitious Soviet military operation involving the landing of amphibious troops onto the Kerch Peninsula. The unit landed near the settlements of Baksi and Adzhimushkay, not far from the Strait of Kerch, and held its position for five months despite withering Axis fire. Beginning in January 1944, it slowly made headway toward Kerch and dislodged the defending Axis troops from one portion of the city. Members of the division distinguished themselves once more, the most prominent of them being field-engineer Jahan S. Karakhanyan, who was killed in December 1943 while trying to establish a new observation post and posthumously awarded with the medal of the Hero of the Soviet Union. In recognition of its efforts, on 24 April 1944 the division was awarded with the Order of the Red Star.
In May 1944, the Soviet army began its offensive to retake Sevastopol. The 89th Division was given the objective of capturing the Gornaya Height, which would then open the way to Sevastopol. This was accomplished and the unit subsequently took part in Sevastopol's and the promontory of Kherson's recapture. For the liberation of the Sevastopol the division was bestowed with the Order of the Red Banner. Senior Lieutenants Simeon K. Baghdasaryan and Khoren A. Khachaturyan, and Senior Sergeants Aydin Gh. Harutyunyan, Harutyun R. Mkrtchyan and Vardges A. Rostomyan were awarded with the Order of the Hero of Soviet Union.
In October–September 1944, the division was transferred first to Brest and then deployed along the defensive line near Lublin. With the commencement of the Vistula–Oder Offensive on January 12, 1945, the 89th Division took part in the general advance into Poland and aided in the liberation of dozens of Polish settlements and towns. By February, it had crossed the Oder River and had taken control of the approach leading to Frankfurt an der Oder and prevented the Germans from breaking through to endanger the Soviet forces now converging onto Berlin. By now, the unit was formally referred to as the "Little Armenian Land" (Haykakan Malaya Zemlya). With these routes secure, the Soviets now prepared for the capture of Berlin. The 89th Division entered Frankfurt an der Oder on April 16 and was then integrated into the command of the 3rd Shock Army. Unit veteran Arshavir Hakobyan writes that many of the Armenians of the division expressed a particular eagerness to take part in Berlin's capture on account of the role the German Empire as an ally of the Ottoman Empire during the 1915 Armenian Genocide.
The 89th arrived in the German capital on the night of April 29, along with other elements of the 3rd Shock Army, and deployed the 390th, 400th, and 526th Regiments to take part in heavy street-to-street battles in the Wedding and Reinickendorf districts.The division's artillery was put to good effect to level buildings where lurking panzerfaust teams were holding up the unit's advance into the central part of the city. On April 30 the division had encountered the twin four-story structures at Flakturm III at Humboldthain Park. Safaryan ordered that they be encircled, and brought his artillery to bear against the flak towers and had his sappers lay a thousand kilograms of explosives at the foundations. Though they caused a great number of casualties, including inflicting concussions against the defenders within, they were unable to penetrate the four meters of iron and concrete walls. But under withering artillery and anti-tank gun fire, on May 2 the commander of the flak towers agreed to surrender.
In several days of fighting the division had overran seven districts. For its role in the capture of Berlin, the 89th was awarded with the Order of Kutuzov 2nd Class and Major General Hmayak G. Babayan was bestowed with the Hero of the Soviet Union. The 89th Rifle Division is recorded to have liberated a total of 900 cities, towns, and villages. It had advanced a distance of 3,700 kilometers in its combat history, and 7,333 of its members were given commendations and awards, nine of whom were decorated with the award of the Hero of the Soviet Union. A "friendship monument" and memorial was erected in the division's honor in Sevastapol.
On the morning of May 3, the 89th was dispatched westward and four days later arrived on the east bank of the Elbe River, near Wittenberg.
Until 1957, the division remained the 89th Rifle Division, when it was re-organized and became the 145th Mountain Rifle Division; in 1965 it became the 145th Mountain Rifle Division; in 1989 it was 145th Mountain Rifle Division. It was based in Batumi, Georgia, for most of the postwar period as part of the Transcaucasian Military District's 9th Army. It comprised the 35th, 87th, 90th, 1358th Mountain Rifle Divisions and 114th Independent Tank Battalion in 1989-90.
The division's installations lined the main roads of Khelvachauri, with at least two barracks blocks, military family housing, and what appears to be a vehicle park or ammunition storage facility which has been hollowed out of gently rolling terrain and camouflaged. There is also a military training area on the coast at Akhalsopeli just south of the Batumi airport.
It was renamed the 12th Military Base on May 15, 1992 according to the Collective Security Treaty. In late 1999, the base had 1,790 personnel and included the 35th (Batumi) and the 90th (Khelvachauri) motor rifle regiments; the 809th artillery regiment (Batumi); the 122nd communications battalion (Medjinistzqali); the 61st artillery detachment (Batumi); and the 773rd reconnaissance battalion (Medjinistzqali). An unnamed Russian Defence Ministry official, speaking to ITAR-TASS on 29 March 2004, said that the two bases had reduced their personnel – "if there were over 2,000 servicemen at each Russian base at the beginning of 2003, now there are at least 1,000 servicemen." The reorganization had also meant the disbandment of units at the bases that did not carry out direct combat missions.
Following several years of tense negotiations, Russia agreed, in March 2005, to complete the withdrawal of the base from Batumi before the end of 2008. However, the base was officially handed over to Georgia on 13 November 2007, ahead of planned schedule.
Honorifics included Tamanskaya Krasnozamennaya, of Order of Kutuzov and Order of the Red Star.