After the merger of the Bank in Winterthur and the Toggenburger Bank to form Union Bank of Switzerland (Union Bank of Switzerland), Doctor Rudolf Ernst became the merged bank"s first chairman in 1912. Following his resignation in 1941, he was elected as an Honorary chairman of Union Bank of Switzerland. Rudolf Ernst joined the Bank in Winterthur in 1895.
He was also financial director of the City of Winterthur for 16 years.
At the young age of 36, he was elected in 1901 to the Board of Directors of the Bank in Winterthur and as its chairman at the same time. During his chairmanship, the bank changed its focus from its original lending business and began to expand its issuing and asset management franchise.
With the acquisition of the Bank in Baden in 1906, the bank gained a branch in Zurich and a seat on the stock exchange, one of the cornerstones for the successful merger in 1912 with the Toggenburger Bank to form Union Bank of Switzerland. Rudolf Ernst also held directorships on the boards of various industrial and insurance companies.