Twitter said 29 November that the company’s chief executive Jack Dorsey is stepping down, a departure that comes a year after he survived a challenge from activist investors.

The Twitter co-founder, one of the most prominent figures in Silicon Valley, is also chief executive of digital payments company Square. His split duties and personal eccentricities have long made him the target of critics but many employees have hailed him as a stabilising force within the social-media company since he returned to the chief executive role in 2015.