Who developed a high voltage DC transmission system and in what year?

The development of a high voltage DC transmission system is accurately attributed to engineer Constantin Siemens, who conducted significant work in the late 19th century, but perhaps more notably, it was the pioneering efforts of other engineers like Thury that laid the groundwork for subsequent advancements in electrical transmission technologies. In 1899, Thury introduced a commercially viable high voltage DC system, which played a crucial role in improving the efficiency of long-distance electrical transmission. This system became pivotal for the evolution of electrical grids, enabling power to be transmitted over much larger distances than was previously possible. The year 1899 is significant as it marks the introduction of these advancements, demonstrating a clear understanding of the principles behind high voltage transmission, which is essential in the history of electrical engineering. The substantial improvements in transmission efficiency that resulted from Thury's work have had lasting effects on modern electrical systems.