In Australia, National Australia Bank, a staid, traditional institution was one of the first, hiring Glenn Barnes from Mars Confectionery. Barnes ultimately was one of two candidates for CEO, losing out to Frank Cicutto.
Don Mercer, ANZ's CEO in the 90s came out of marketing at Shell.
The 90s also brought disintermediation into banking, the idea that non-bank institutions could undertake some of the activities traditionally done by banks and do it more cheaply, if not better.
It sparked a run of management consultants into banking from firms like McKinsey & Co, The Boston Consulting Group and First Manhattan.
In Australia, Ahmed Fahour, who ran NAB's Australian business was from BCG while Brian Hartzer, now Westpac Banking Corp CEO, was from First Manhattan and Commonwealth Bank boss Ian Narev is ex-McKinsey.
In ANZ's recent restructure, another ex-McKinsey consultant, Fred Ohlsson, was promoted to head the Australian bank.
Industrialists too have had their moment as banks looked at “unbundling” their businesses into the components of product manufacture and delivery. And retailers.
These trends have been reflected around the world.
But there're two strands of thinking at play here. One is diversity: is it good to bring a variety of skills and knowledge sets into banking, particularly as the traditional demarcations between industries break down? The answer is unequivocally yes.
That's true not just for senior executives but down through the ranks and up to board level. The evidence is unequivocal that having people who think differently adds to innovation and resilience.
But the other strand is who is going to be the best CEO for any given institution.
This is a much harder question and it's the one which is rightly the central reason for the existence of a board. Boards are important in monitoring strategy, casting an obsidian eye on risk, setting an example on culture. But ultimately their biggest responsibility is hiring and firing CEOs.
In the 90s and 00s boards fell – as did shareholders – for the Cult of the CEO, the Celebrity CEO, the one person who could turn an organisation around, set it on a new course, manage it through eventful times.
Of course, no such person exists. Cultures and team work are more important than individuals. General Electric's Jack Welch was one of the most celebrated CEOs and he grew the company enormously.
But it has been his much lower key successor, Jeffrey Immelt, who has done more to prepare GE for a radically different future, one without the domestic hardware of its earliest years and without the massive non-bank financial services business Welch built which de-railed GE during the financial crisis.
So should banks be looking for technologists?
One of India's vibrant new “banks”, the mobile and e-commerce platform Paytm, is pondering exactly that. The rapidly expanding company needs to hire hundreds of new executives. But at the most senior levels, including CEO, it doesn't want bankers.
“Our CEO will not be an ex-banker. We do not want more of the same. We want a new, fresh-thought process. However, in departments such as compliance, finance and treasury, we want banking people because this is where the banking core is,” Vijay Shekhar Sharma, the founder of parent company One97 told India's Business Standard.
“People who have horizontal experience in multi-sectors work out better”, he said, noting sectors like fast moving consumer goods and telecoms were among the hunting grounds for the chief executive. “This is a new business model. So, we need people who are risk takers and want to try new things.”
So what background should bank CEOs have? History tells us none in particular.
Consider three of the most successful bank CEOs of recent history in Australia. Ralph Norris, who set CBA up as the market leader, did have a technology background but he came to the bank from an airline.
David Morgan who positioned Westpac ideally to weather the risk of the financial crisis came out of government treasury and ran Westpac's institutional bank.
John McFarlane at ANZ was a career banker.
There is no pattern here and indeed to look for one is to fall victim to the very human trait of apophenia – false pattern recognition. Humans look for patterns and it has been very useful in surviving and adapting across a huge variety of environments.
But it also leads us to seek – and find – patterns where none exist. We may believe data and analytics are telling us something definite when in fact the data sets are either of too poor quality or too small for any such conclusions.
The next CEO of ANZ or any of a number of banks may be a technologist (although it is worth noting before Google Carnegie spent 20 years at Proctor & Gamble). But they may be a retailer or a rocket scientist or a banker.
There may well be data sets which analytics can interpret to identify who exactly would make a great CEO – but if there are they are going to be a lot more complex than where someone worked before.
What the data do tell us is successful companies are resilient and innovative, to do that they need engaged staff who are prepared to offer discretionary effort, and they need to understand rapidly changing environments and customer behaviour.
That requires a leader of particular qualities. But the data and analytics don't give us a formula for what they are and how to measure them.