By now, Apple's recent misadventures in maps are well documented. But a new report in AllThingsD helps to shed light on just how we got here. According to the site's sources, Apple pushed out Google Maps for one reason above all else: turn-by-turn directions.

For years, the version of Google Maps available on Android offered voice-guided turn-by-turn directions while the iOS version did not. The feature wasn't included in the two companies' original agreement, and negotiations to add it continually broke down.

Google didn't want to just hand over turn-by-turn, which it knew was highly valuable to customers and it had spent a lot of time and money developing. It asked Apple to give it in-app branding and to consider integrating other Google services like Latitude, which allows users to see where their friends are on a map. Apple declined.

Uneasy with the idea of being beholden to Google for one of the iPhone's core features, and increasingly concerned that it was at a disadvantage to Android, the Cupertino company began developing its own maps alternative with the plan of rolling it out sooner rather than later.

Read the full report over at AllThingsD.