The 305 mm howitzer M1939 (Br-18) (Russian: 305-мм гаубица образца 1939 года (Бр-18)) was a Soviet superheavy siege howitzer used by the Soviet Union during World War II. After the Germans occupied Czechoslovakia in March 1939 they took over the Škoda Works, which had been working on this (Skoda XV) design and a companion 210 mm gun (Skoda VX). After a successful test firing 5 July 1939, as a result of the Molotov–Ribbentrop Pact the Germans sold both designs to the Soviet Union. It is not entirely clear that Skoda actually built the weapons itself or merely supplied the blueprints. At any rate, very few weapons seem to have been built; so few, in fact, that there is no record of the Germans capturing any during Operation Barbarossa.