Orginally from Bandon, Co Cork, and one of nine children, he spent many of his formative years in Britain where the family moved when he was young. His accent is softly English, inflected with rolled Irish ‘Rs’ and a hint of the US.

A history degree from Oxford University was his passport into the polished world of investment banking – where he rose through the ranks in the go-go 1990s and numbered among legendary Morgan Stanley boss John Mack’s top executives.

Never the kind of banker to have his own publicist, Kelleher’s rise through the ranks in London and New York was low-key but no less stratospheric. In his last year’s at Morgan Stanley, his total pay clocked in around the $20m mark. Inside the bank, he was known for an arch sense of humour and encyclopaedic historical awareness.  

When Mack retired in 2010, Kelleher missed out on the top chief executive’s spot to James Gorman – an Australia-born member of the Irish diaspora who hails from an even bigger family than Kelleher as one of 12 children.

If his ego was bruised by not getting the CEO job, Kelleher didn’t let it show, staying on as Gorman’s number two and later still as an adviser when he retired from day-to-day banking in 2019.

His longevity and stints as chief financial officer and president made him among the most powerful figures to stalk the bank’s corridors of power.

That included invaluable experience during the global financial crisis of 2008. Morgan Stanley was among a handful of global banks that emerged battered rather than shattered from the subprime crisis that sank or swamped rivals like Lehman Brothers, Bear Sterns and Merrill Lynch.

Under John Mack and key lieutenants, including Kelleher who as CFO had the tough job of ensuring the bank’s vital liquidity through periods of extreme uncertainty, Morgan Stanley was able to resist pressures including from Barack Obama’s powerful treasury secretary Tim Geithner, to be submerged into a bigger player.

They did it by being upfront earlier about the scale of their issues, taking support where they could and high-stakes commercial diplomacy that held off Geithner long enough to secure outside investment from Japan’s Bank of Tokyo Mitsubishi.

A similar mix of pragmatism and toughness was on display this weekend. Kelleher and UBS CEO Ralph Hamers toughed it out as the Credit Suisse talks went to the wire to extract massive concessions from Swiss regulators that will leave UBS with the best parts of its hometown rival for a knockdown price.

Kelleher joined UBS in 2020, signing on for a 10-year term and helping clarify the bank’s strategic commitment to being the money manager of choice to the world’s super-rich. The Credit Suisse takeover won’t distract from that.

Unlike the forced mergers of the 2008 crisis, UBS is not inheriting a sinking bank’s toxic loan assets. It will take over lucrative wealth management and retail businesses at knockdown prices, including Credit Suisse’s Swiss domestic bank, while, as Kelleher himself indicated, moving to aggressively wind down the investment banking businesses it doesn’t like.

Even if it looks like a good deal long-term for UBS, the pace of Credit Suisse’s demise means Kelleher and Hamers are out on a limb. Unlike a traditional bank merger, the rescue deal allows no time for traditional due diligence, external advice or even shareholder endorsement.

Pulling that off takes nerves of steel as well as decades of experience, and Kelleher is still only in the early phase of his chairmanship.