Not too long ago, Norton Rose looked like an also-ran.

The London-based firm, known for its financial institutions practice, stumbled badly after its offices were bombed—twice—by Irish Republican Army terrorists in the early 1990s. It jumped belatedly on the global bandwagon, establishing a network of European offices that did not turn a profit for half a decade. By the early 2000s, key partners were running for the exits. The Magic Circle, formerly Norton Rose’s closest rivals, had pulled far ahead.