Light emitting diodes (LEDs) are now widely used for their efficiency, brightness, and low cost in various applications. However, their development was long and challenging. Electroluminescence, the principle behind LEDs, was first observed in 1921 by H.J. Round, but his findings were not pursued further for many years. Oleg V. Losev, a Russian scientist, later rediscovered electroluminescence in silicon carbide and made significant contributions to the development of LEDs. He also correctly identified the p-n junction, a key component in LEDs, but his work was largely unrecognized during his lifetime. Losev's research was cut short by the German invasion of Russia, and he died in 1942. It took over a decade after his death for LED research to advance further. In 1955, the first modern LEDs were developed using III-V single crystals and germanium-silicon alloys. A major breakthrough came in 1970 when researchers produced laser light from gallium arsenide crystals. LEDs became commercially viable in 1968 with the introduction of GaAsP LED displays. The development of LEDs has been influenced by many factors, including the timing of technological advancements and the recognition of early pioneers. The history of LEDs highlights the importance of perseverance and innovation in scientific research. The Materials Research Society also offers a short course program on materials science topics for the 1987 Spring Meeting.Light emitting diodes (LEDs) are now widely used for their efficiency, brightness, and low cost in various applications. However, their development was long and challenging. Electroluminescence, the principle behind LEDs, was first observed in 1921 by H.J. Round, but his findings were not pursued further for many years. Oleg V. Losev, a Russian scientist, later rediscovered electroluminescence in silicon carbide and made significant contributions to the development of LEDs. He also correctly identified the p-n junction, a key component in LEDs, but his work was largely unrecognized during his lifetime. Losev's research was cut short by the German invasion of Russia, and he died in 1942. It took over a decade after his death for LED research to advance further. In 1955, the first modern LEDs were developed using III-V single crystals and germanium-silicon alloys. A major breakthrough came in 1970 when researchers produced laser light from gallium arsenide crystals. LEDs became commercially viable in 1968 with the introduction of GaAsP LED displays. The development of LEDs has been influenced by many factors, including the timing of technological advancements and the recognition of early pioneers. The history of LEDs highlights the importance of perseverance and innovation in scientific research. The Materials Research Society also offers a short course program on materials science topics for the 1987 Spring Meeting.