Margaret of Anjou England to prove himself before she followed. He did so, restoring Henry VI briefly to the throne on 3 October 1470. By the time Margaret, her son and daughter-in-law (Anne) were ready to follow Warwick back to England, the tables had again turned in favour of the Yorkists, and the Earl was defeated and killed by the returning King Edward IV in the Battle of Barnet on 14 April 1471. Margaret was forced to lead her own army at the Battle of Tewkesbury on 4 May 1471, at which the Lancastrian forces were defeated and her seventeen-year-old son Edward of
IEEE 1471 Standards Board approved the specification as IEEE Std 1471-2000. In 2006, ISO/IEC Joint Technical Committee 1 (JTC1), Information technology/Subcommittee SC 7, Software and systems engineering, adopted the specification as ISO/IEC 42010, under a special "fast-track procedure", in parallel with its approval by national bodies of ISO and IEC. A coordinated revision of this standard by ISO/IEC JTC1/SC7/WG42 and IEEE CS commenced in 2006, following the successful ISO/IEC fast-track ballot and in line with the IEEE standard 5-year review of the standard. In November 2011, IEEE 1471-2000 and ISO/IEC 42010:2007 was superseded by ISO/IEC/IEEE 42010:2011, "Systems and software engineering — Architecture