Lord Fisher, full name John Arbuthnot Fisher, was a prominent British naval officer and reformer in the early 20th century. Born in 1841, he played a crucial role in modernizing the Royal Navy, advocating for new technologies like the dreadnought battleship and the use of submarines. His innovative ideas significantly influenced naval strategy during a time of rapid change. Fisher served as the First Sea Lord from 1904 to 1910 and again during World War I. He was known for his strong personality and sometimes controversial decisions, which earned him both admiration and criticism. His legacy remains significant in naval history.