**Edgar Frank Codd** (19 August 1923 – 18 April 2003) was a [[United Kingdom|British]] [[Computer scientist|computer scientist]] who, while working for [[IBM]], developed the [[Relational model|relational model]] of [[Database|database]] management, one of the most influential theoretical contributions in the history of [[Computer science|computer science]]. His 1970 paper "A Relational Model of Data for Large Shared Data Banks," published in the journal [[Communications of the ACM]], introduced the mathematical foundations of [[Relational database|relational databases]] and fundamentally transformed how data is organized, stored, and queried. Codd was awarded the [[Turing Award]] in 1981 in recognition of his contributions to database systems theory. Born on the [[Isle of Portland]], [[Dorset]], England, Codd studied mathematics and chemistry at [[Exeter College, Oxford]] before serving as a pilot in the [[Royal Air Force]] during [[World War II]]. He emigrated to the [[United States]] in 1948 and joined IBM in 1949, eventually working at the company's research laboratories in [[San Jose, California]]. Drawing on [[Set theory|set theory]] and [[First-order logic|predicate logic]], Codd developed a rigorous mathematical framework for representing data as [[Relation (database)|relations]]—two-dimensional tables of rows and columns—and for manipulating that data through operations formalized in [[Relational algebra|relational algebra]] and [[Relational calculus|relational calculus]]. Codd's relational model provided the theoretical basis for [[SQL|Structured Query Language]] (SQL) and the relational database systems that came to dominate enterprise computing, including [[Oracle Database|Oracle]], [[IBM Db2|IBM DB2]], and [[Microsoft SQL Server]]. He later articulated his design principles in the form of [[Codd's 12 rules|Codd's 12 rules]], a set of criteria for evaluating whether a database management system could be considered truly relational. Codd also contributed to the theory of [[Database normalization|database normalization]], defining the first three [[Normal form (database theory)|normal forms]] as a means of reducing [[Data redundancy|data redundancy]] and improving [[Data integrity|data integrity]]. His work established the intellectual foundation for much of modern [[Data management|data management]] and continues to shape database research and practice.