Xapo Bank's own company page names him as the founder and dates the company to 2013. It gives the founding motive as his experience of hyperinflation in Argentina, and the aim as holding life savings in Bitcoin rather than in a currency that could be inflated away. What the company built first was storage: a wallet, and a vault service run out of physical sites.
Xapo's own blog referred to him in October 2019 as "Xapo CEO, Wences Casares". That was two months after the company announced the sale of its Institutional Custody Business to Coinbase, a decision the company explained in its own words as a choice to concentrate on its consumer side.
The Gibraltar entity that now holds the banking permission is run by a different chief executive, and its licences and structure are set out on the Xapo Bank entry rather than here.