Question: Which war did the operator of the Finnish coastal defence ship Ilmarinen serve in?

Knowledge 1: Finnish coastal defence ship Ilmarinen
Ilmarinen was a Finnish Navy "Panssarilaiva" ("Armored ship"; a coastal defence ship by British classification). The unit was constructed at the Crichton-Vulcan shipyard in Turku, Finland, and named after the mythological hero Ilmarinen from the Finnish national epic, the Kalevala. "Ilmarinen" was the flagship of the Navy from 1 May 1933 until her demise on 13 September 1941. [SEP] Knowledge 2: Finnish Navy
When the Winter War broke out the Finnish Navy moved to occupy the de-militarized Åland Islands and to protect merchant shipping. In the first month of the war, battles between Soviet ships and Finnish coastal batteries were fought at Hanko, Finland, Utö and Koivisto. At Koivisto and Hanko, the batteries forced Soviet battleships to retire with damage. Finnish efforts to use submarines ("Vesikko" and "Saukko") to sink Soviet capital ships failed. In December 1939 the ice became so thick that only the ice-breakers could still move. The two coastal defence ships were moved to the harbour in Turku where they were used to strengthen the air-defences of the city. They remained there for the rest of the war.
Knowledge 1: Finnish coastal defence ship Ilmarinen
Ilmarinen was a Finnish Navy "Panssarilaiva" ("Armored ship"; a coastal defence ship by British classification). The unit was constructed at the Crichton-Vulcan shipyard in Turku, Finland, and named after the mythological hero Ilmarinen from the Finnish national epic, the Kalevala. "Ilmarinen" was the flagship of the Navy from 1 May 1933 until her demise on 13 September 1941. [SEP] Knowledge 2: Taisto-class motor torpedo boat
In 1943, the Finnish Navy was in great need for new motor torpedo boats and the Finnish ship designer Jarl Linblom studied the Finnish Navy's Italian-designed motor torpedo boats and improved the design. The improved hull design gave them better seaworthiness and the boats could reach up to without armament. Six were manufactured at "Turun Veneveistämö" during the war, and called the "Taisto class".
Knowledge 1: Finnish coastal defence ship Ilmarinen
Ilmarinen was a Finnish Navy "Panssarilaiva" ("Armored ship"; a coastal defence ship by British classification). The unit was constructed at the Crichton-Vulcan shipyard in Turku, Finland, and named after the mythological hero Ilmarinen from the Finnish national epic, the Kalevala. "Ilmarinen" was the flagship of the Navy from 1 May 1933 until her demise on 13 September 1941. [SEP] Knowledge 2: Franco-Prussian War
To relieve pressure from the expected German attack into Alsace-Lorraine, Napoleon III and the French high command planned a seaborne invasion of northern Germany as soon as war began. The French expected the invasion to divert German troops and to encourage Denmark to join in the war, with its 50,000-strong army and the Royal Danish Navy. It was discovered that Prussia had recently built defences around the big North German ports, including coastal artillery batteries with Krupp heavy artillery, which with a range of 4,000 yards (3,700 m), had double the range of French naval guns. The French Navy lacked the heavy guns to engage the coastal defences and the topography of the Prussian coast made a seaborne invasion of northern Germany impossible.

Answer: Winter War