The foundations for thermonuclear fusion research were laid in 1905 by Albert Einstein and by Francis William Aston, who showed in 1920 that the conversion of hydrogen into helium could release large amounts of energy. Fusion was first achieved in a thermonuclear bomb (Ivy Mike, 1952). A controlled thermonuclear fusion reaction was achieved in 1958 in the theta-pinch device Scylla I. The stellarator principle was used in Lyman Spitzer’s Model A Stellarator in 1953, and the tokamak T-1 started operation in 1958 in Russia. Construction of ITER, the largest tokamak ever built, started in 2007. On 5 December 2022, the laser-driven fusion facility NIF achieved ignition for the first time.