Short answers, pulled from the story.
The T-72 began its first production run in 1972 at Nizhny Tagil. A final trial batch was built as Object 172M and tested in 1973, with the tank officially accepted into Soviet Army service in 1974.
About 25,000 T-72 tanks have been built. Refurbishment has enabled many to remain in service for decades, and production and development of modernized T-72 models continues today.
The T-72 was developed at Uralvagonzavod in Nizhny Tagil under the Uralvagon KB design bureau, originally led by Leonid Kartsev and later by Valeri Venediktov. It emerged from a rivalry with the Morozov KB in Kharkiv, which produced the T-64.
Penetrating hits to the T-72 can trigger a chain reaction that detonates all stored ammunition, blowing the turret off the hull. This vulnerability was first observed during the Gulf War and is primarily linked to spare ammunition stored outside the autoloader's ballistic protection.
Iraqi T-72s performed well in the Iran-Iraq War, with only 60 tanks lost over eight years of fighting. In one engagement, the 10th Iraqi Armoured Brigade with T-72 tanks destroyed the 16th Iranian Armoured Division equipped with Chieftain tanks in approximately 12 hours.
The T-72 has seen service in over 40 countries and in numerous conflicts, including the Iran-Iraq War, both Gulf Wars, the Chechen Wars, the Syrian Civil War, the Russo-Georgian War of 2008, and the ongoing Russian invasion of Ukraine.