Duke was founded in 1972 originally as an industrial developer. Its first development project was Building One at Park 100 in Northwest Indianapolis. The company still owns a significant portion of the park.

During the 1970s, the company expanded both geographically and in product type, adding office properties to its portfolio and moving into Cincinnati by the latter part of the decade. The 1980s saw Duke pushing into other Midwest markets, including Detroit, Nashville, Tenn., and Columbus, Ohio. During the same time, it was bulking up its industrial, office and retail offerings, working primarily as a developer on land the company already owned.

Along with a wave of other REITs that went public under the UPREIT structure in the early 1990s, Duke went public in October 1993. That year kicked off a new era of expansion for Duke during which offices were opened in Cleveland, Minneapolis, St. Louis and Chicago throughout the mid-1990s.

"We really grew the company from the time we went public, going from a company of around $600 million to a company worth about $3.5 billion at the end of 1998," says Dennis Oklak, Duke's chairman and CEO. "We continued to expand and did acquisitions and new development (in our new markets)."

In 1999, Duke pressed beyond the bounds of being a Midwestern company, merging with the Atlanta-based Weeks Corporation. For Duke, the move was an entry into the Southeastern region. Today the company has holdings in Atlanta, Dallas, Orlando, Raleigh, Tampa and south Florida.

"Since that time until recently, we've really focused on development in those cities and in our office and industrial properties," Oklak says. "We really didn't do any geographic expansion from the time of the Weeks merger in 1999 through 2004. Mainly, the reason for that was that the economy was down a little bit and our business on the office and industrial side was also down a little bit, so we did not see opportunities to really grow as quickly with a down economy."

Instead, the company continued to operate heavily in its existing markets. At the same time, Duke began to recycle its capital by selling off older assets. "That really culminated in September 2005, when we disposed of a $1 billion portfolio of flex and light-industrial properties in eight of our markets," Oklak says. "We wanted to get out of that product type to focus on large bulk-industrial products."