When war broke out in September 1939, Cardiff docks constituted the biggest coal exporting port in the United Kingdom, maybe even the world.
Craddock Street in Cardiff
Sitting on the flat coastal plain below the twin Rhondda valleys, Cardiff sent out a much greater tonnage of coal than any other British port, including the bigger and more renowned docks of places like London, Newcastle and Liverpool.
Therefore, it was inevitable that, as the aerial war developed, the city and its docks would become a major target for enemy bombers. And yet, in those early war years, nobody really had the slightest inclination of what was to come.
The first German air raid on Cardiff took place on 3 July 1940, only a few weeks after the fall of France. Previously, the Welsh port had been virtually out of range for the German Dornier and Junkers bombers but with captured French airfields now in enemy hands the war came suddenly close, terrifyingly close, for the people of south Wales.
Further raids on Cardiff occurred that year on 10 and 17 July, and then again on 7 August. They were just the start of a four year bombing offensive but they were terrifying occasions for the city's populace - air raid sirens screaming, the wail of bombs hurtling through the air, the crump of anti-aircraft shells, smoke, dust and rubble and, always, the thought of red-hot pieces of metal cutting into human flesh.
The next year, 1941, saw dozens of raids, particularly in the spring and early summer months when, sometimes, it seemed as if the bombers would appear every single night of the week. There were fewer raids in 1942, the most noticeable being an attack on 17 May. It was widely believed that this was a retaliation for the famous Dambuster Raids on the German industrial centres and hydro-electric dams earlier in the year.
The final attack on Cardiff came, surprisingly when you consider the state of German armaments, as late as March 1944. During this raid Cardiff station was hit and for a while it looked as if the main Cardiff-London railway link would be severed.
Strangely, there was also an air attack on Cork in neutral Ireland at this time. The pilot and navigator mistook the Irish town for Cardiff, believing that they were over, not the Irish Sea but the River Severn! Diplomatic incidents had been started by less.
In all more than 2,100 bombs fell on Cardiff during the war years. They caused 355 deaths and at least 500 injuries.
Hundreds of houses and business premises were damaged or destroyed in the four years of heavy and sustained bombing, particularly in the western end of the city.
Cardiff's worst night was 2 January 1941 when a fleet of over 100 German planes droned in across the Severn Estuary. There was a full moon that night - a 'bombers moon' as they called it - and the whole of Cardiff, docks and town, were illuminated as if it was day. Over 350 homes were destroyed in the raid that began just after 6.30pm and lasted for a horrifying ten hours.
Llandaff Cathedral was badly damaged and both the Canton and Riverside areas were also seriously hit. A total of 165 people were killed in the raid, 116 of them coming from the Canton and Riverside communities. Fifty people from just one street in Riverside became casualties.
Site of Hollyman's bakery on Corporation Road in Grangetown
The saddest story about the raid concerned Hollyman's bakery on the corner of Stockland Street and Corporation Road in Grangetown. Mr Hollyman had a huge cellar under his house and business and as the raid began he encouraged people to come and take shelter. Unfortunately, the building took a direct hit and 32 people were killed, including at least five members of the Hollyman family.
Sometimes, however, there were funny sides to the German raids, particularly for the children of the city who were more concerned about collecting shrapnel than they were with potential danger. Alan Worrell particularly remembered one incident involving the old swimming pool in Splott Park:
"We were crowded into the swimming pool and, believe me, they really used to jam them in. The air raid warning went but we didn't hear it. The pool attendant came round shouting 'Everybody out of the pool.' So we got out, just as we were, in our bathing costumes, and went across the road into Baden Powell School which had air raid shelters. And we spent the rest of the afternoon in those shelters, just sitting there with our bathers on."
(from "Wales at War", Gomer Press)
Clearly the memory of those cold and wet bathing costumes and the dank, dark air raid shelter - when he should have been enjoying himself in the swimming pool - has stayed with him!
In all, nearly 1,000 people across Wales were killed in air raids during the war. Most of these came from Cardiff and Swansea but other, smaller communities suffered as well. As far as the people of the capital city are concerned, however, they will never forget the dreadful memories and the horror of the four-year Cardiff Blitz.
BBC Wales News created as series of articles to mark the anniversary of the heaviest night of bombing during the Cardiff Blitz on 2 January 1941.
Keith Matheson - My memories of the Cardiff Blitz Keith Matheson shares his memories of the night that German bombs fell on the Welsh capital 70 years ago, the worst night of the Blitz in Cardiff.