It used to be the Ewings who livened up the boardrooms (and saloon bars) of Dallas, but these days the Rockefellers provide all the dynastic entertainment on offer. At ExxonMobil's annual shareholders meeting in the Texan city last week, descendants of John D. Rockefeller, the founder of Exxon's forebear Standard Oil, lobbied hard to force the company to split the joint role of chairman and chief executive - currently held by Rex Tillerson - in two.

Most shareholders demurred. They seemed happy enough with the company's performance. As well they might be: ExxonMobil had record earnings of $40bn(£20bn) last year, far outstripping all other leading US corporations. The share price, up by 10 per cent in the past 12 months, has shaken off the bearish sentiment that has afflicted other industrial stocks. It has not been a bad time to be in the oil business, of course. But management must be getting something right.