Alan Turing, an iconic figure in the world of computer science, made significant contributions that laid the groundwork for the field of artificial intelligence. His work during the mid-20th century not only helped the Allies win World War II but also provided a conceptual framework that continues to influence AI research today. At the heart of Turing's contributions is the Turing Test, a measure for determining whether a machine can exhibit intelligent behavior equivalent to, or indistinguishable from, that of a human.

Born in 1912, Alan Turing displayed an aptitude for mathematics and logic from a young age. Educated at Cambridge and Princeton, Turing developed an interest in the nascent field of computer science. His 1936 paper, 'On Computable Numbers,' introduced the concept of a theoretical computing machine, now known as the Turing Machine, which could simulate the logic of any computer algorithm. This foundational idea established the principles upon which modern computers operate.

Turing's most famous contribution to AI is the Turing Test, introduced in his 1950 paper 'Computing Machinery and Intelligence.' The test involves a human evaluator who interacts with both a human and a machine. The evaluator does not know which is which and must determine which participant is human based solely on their responses. If the evaluator frequently fails to distinguish the machine from the human, the machine is said to have passed the test, demonstrating a form of artificial intelligence.

The Turing Test has sparked considerable debate and research within the AI community. Many scientists and philosophers have engaged with the test's implications and limitations. While some argue that passing the Turing Test is a significant milestone for AI, others contend that it measures only superficial aspects of human intelligence. Nevertheless, the test remains a touchstone in discussions about machine learning, consciousness, and the future of AI.

Turing's work extended beyond theoretical contributions. During World War II, he played a crucial role in breaking the German Enigma code, a feat that significantly shortened the war. His contributions to cryptography were instrumental in the development of early computers, like the Bombe, used for codebreaking. Turing's achievements in this area demonstrated the practical applications of his theoretical ideas.

Despite his profound contributions to science and society, Turing's life was marred by tragedy. In 1952, he was prosecuted for homosexuality, which was then illegal in the UK. He was subjected to chemical castration as an alternative to prison, a punishment that led to his untimely death in 1954. In 2013, the British government posthumously pardoned Turing, acknowledging the injustice he faced.

Alan Turing's legacy lives on in numerous ways. The Turing Award, often dubbed the 'Nobel Prize of Computing,' honors individuals who have made lasting contributions to the field. His life and work continue to inspire researchers, highlighting the intersection of computation, ethics, and human potential. As AI evolves, Turing's pioneering ideas remain central to our understanding of machine intelligence and its capabilities.

In conclusion, Alan Turing's role in the history of AI is monumental. His theoretical and practical contributions laid the foundations for modern computing and artificial intelligence. The Turing Test, despite its controversies, remains a pivotal concept in assessing machine intelligence. Turing's work continues to influence AI research, reminding us of the profound impact one individual's ideas can have on the future. As we advance in our quest to create intelligent machines, we stand on the shoulders of giants like Alan Turing, whose genius and perseverance continue to guide us.