ESV

Ensco Rowan Plc

A maker of offshore drilling rigs and services, Ensco Rowan Plc helped oil and gas companies drill wells in deep water around the world. It was born in 2019 when two veteran drillers merged: Ensco, whose name comes from "Energy Services Company," and Rowan, founded in 1923 by brothers Charlie and Arch Rowan in Texas. The combined company soon renamed itself Valaris, a nod to the Latin word for "strength."