The Christiana Bank & Trust Company formed in 1992 to conduct a banking and trust business for Greenville, Delaware, and nearby communities in New Castle County, Delaware, and Chester County, Pennsylvania. In 1988 two banking executives, Philip W. Seibold, Jr. (1937-2010) and John J. Nesbitt, III (1941-2019), while tailgating at Winterthur for the annual steeplechase race, discussed the possibility of starting a new bank in Greenville, Delaware. At the time, the state of Delaware began changing its banking laws to attract out-of-state banks. Increased marketing for banks, old and new, provided an opportunity for growth in mergers and acquisitions.

Accordingly, Seibold and Nesbitt commissioned an economic feasibility study for the prospect of establishing a successful bank in Greenville. Ultimately, the study recommended the establishment of a bank in the region, citing the strong possibility of success based on numerous factors such as demographics, trends in the number of mutual savings banks in New Castle County, and deposit growth rates.

The organizers of the bank decided to parlay the historic name of the Swedish Queen Christina who reigned at the time of the first permanent settlement in Delaware - they named the bank the Bank of Christiana Hundred. The term "Hundred" had been a unit of local government in England, brought to Delaware and Pennsylvania by William Penn (1644-1718). Representatives from each local Hundred were periodically elected to Delaware's General Assembly. P. Coleman du Pont's (1948-) advertising and marketing firm, Lyons, Inc. recommended changing the name of the bank to Christiana Bank & Trust Company.

In 1992, the Board of Directors elected Robert G. Elder (1940-) as the bank's first President. Elder was a senior banking executive with over twenty-three experience in the field, including high-ranking positions at the Midlantic National Bank of Edison, New Jersey, and the Provident National Bank of Philadelphia.

In 2008 the bank was purchased by National Penn Bancshares, Inc. (NPB) for $56.5 million. The company was held by NPB until December 3, 2010, when the Wilmington Savings Fund Society (WSFS) purchased Christiana, operating the bank as a wholly owned subsidiary, keeping its status as a Delaware chartered banking corporation. WSFS subsequently integrated the trust division as part of its Wealth Management division. At the time of its acquisition by WSFS, the bank's assets were about $161 million in deposits, $112 million in performing loans, and about $7 billion in trust assets.