They never saw it coming.

This week marks the iPhone’s fifth birthday, and that began the end for RIM.

In 2007, the BlackBerry was still on the way up, and the iPhone was not seen as a threat.

“There was a lot of arrogance; RIM’s executives believed they owned the mobile space,” said Steven Brasen, researcher at Enterprise Management Associates. “They did not see this coming.”

A year after the first iPhone, RIM stock was up 120 percent, and the market share for its smartphones almost doubled to 16.6 percent by the end of 2008, according to Gartner data.

Apple went from a 2.7 percent share of the smartphone market to 8.2 percent from 2007 to 2008. Last quarter, Apple had an almost 23 percent share to RIM’s 7 percent.

RIM’s co-founders who oversaw the fast fall, ex-CEOs Mike Lazaridis and Jim Balsillie, have been blamed for not reacting in time to the changing consumer climate. The company owned enterprise smartphones and for a time users were tethered to two devices: the one they wanted, iPhones, and the one their bosses gave them, BlackBerry, Brasen said.