Chicago ? Mayor Richard M. Daley, who wielded more control over Chicago than anyone but his father decades before, said Tuesday he will not seek re-election, bringing a surprising end to a dynasty whose name became synonymous with the city’s legendary political machine.

For all but 13 of the last 55 years, a Daley has ruled City Hall with red-faced temper, garbled syntax and iron fist. The son’s departure threatens to leave a significant power vacuum in the nation’s third largest city, which he helped transform from a gritty industrial hub into a gleaming modern metropolis.

Flanked by his smiling wife, Maggie, who has been battling cancer for years, and their children, Daley called the announcement “a personal decision, no more, no less,” and said he and his family now begin a “new phase of our lives.”