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The full knighthood title bestowed upon John Cockcroft was "Sir John Douglas Cockcroft." This prestigious honor recognized his outstanding achievements and contributions to science. Cockcroft, a distinguished physicist, made significant advancements in nuclear physics and played a pivotal role in the development of particle accelerators. His expertise and dedication to scientific research earned him the esteemed title of "Sir," a testament to his remarkable accomplishments in the field of physics.