Influential missiologist Dr. Ralph D. Winter died Wednesday night after a long battle with cancer. He was 84.

According to Greg Parsons, general director of the U.S. Center for World Mission, Winter died at 9:05 p.m., at his home in Pasadena, Calif., surrounded by his wife, three of his four daughters, and other loved ones.

Winter was in the middle of radiation treatments and had grown “extremely weaker” over the past weekend, the USCWM communications department had reported Monday.

Winter, who founded USCWM and William Carey International University, is widely regarded as one of the key factors behind the major shift of perspective in the mission movement – a shift from going to countries and individuals to penetrating “unreached peoples,” or those who have been bypassed.

He was named by Time magazine in 2005 as one of America’s 25 most influential Evangelicals and founded and served several organizations, including the International Society for Frontier Missiology and the Frontier Mission Fellowship, among others.

Late last year, Winter received the Lifetime of Service Award at the North American Mission Leaders Conference, a major annual mission gathering co-sponsored by The Mission Exchange and CrossGlobal Link.

Winter was honored on the second night of the conference for his work as a mission educator, entrepreneur and paradigm pioneer for more than three decades.

Memorial services have been tentatively set for June 27.