I start here a 4 part mini series (translated from Hungarian, so sorry in advance for the bad translation...) about the S-300 history, adding some might not so well known numbers, to help clarifying the big picture...

S-300 history-I . Quantity or quality?

The analogue era of anti-aircraft missiles peaked at the late seventies, when over 1100 SAM batteries defended the territory of the Soviet Union.

56 fixed C-25 Berkut (SA-1) defended Moscow in a double ring.
The 20 target channel system used command guided missile with 46km range, but were unable to engage targets flying below 500m.



The outer ring was 85~90km, the internal 45~50km from the Kremlin.

The First Air Defense Army consisted of four corps.
1st Air Defense Corps, Vidnoe (purple) defended Moscow from the south-east, with nine outer and five interior regiments
6th Air Defense Corps, Balashikha (light blue) defended Moscow from the north-west defended Moscow, eight outer and six interior regiments
10th Air Defense Corps, Dolgoprudnyi (green) defended Moscow from the north-east defended Moscow, nine outer and five interior regimentss
17th Air Defense Corps, Odnitsovo (dark blue) defended Moscow from the south-west, eight outer and six interior regiments

More than 750 S-75M Volkhov (SA-2) single channel systems were fielded, using command guided missiles with 56km range, and an effective minimum target altitude of 100m.



They protected Leningrad with ~30 systems forming a single ring around the city, plus other medium cities with smaller numbers.
Created the world's longest (8500km), continuous air defense missile belt, that started from Leningrad, down along the Baltic Sea coast, along the Polish, Czechoslovakian, Hungarian, Romanian border, through the north coast of the Black Sea, through the Caucasus...



... and along the borders of Iran, Afghanistan and China, all the way till Mongolia.


~180 S-125 Neva (SA-3) low altitude, single-channel system complemented the firing zones of the S-75s.
Single channel system, using command guided missiles with only 25km range, but with an effective minimum target altitude of 20m.

~130 S-200 Vega (SA-5) long range, typically 2~3 or 5 channel systems were fielded.
They used 255km-range semi-active guided missiles reaching their target over Mach6.
Defended the European airspace part of the Soviet Union (west of the Urals), with mostly overlapping firing zones.
8 pieces formed a ring around Moscow with 100 km radius, plus 8 more created a 800km long north and east defense barrier from 400km of the capital.



So for the Asian part, only the major settlements were defended by sole systems.

Replacing these analogue systems by the multi channel digital S-300 was a Herculean task, limited by the new system 4~5x price tag, and the abrupt end of the Cold War.