NEW YORK (CNNMoney) -- Almost immediately after Google lost the bidding for a package of Nortel patents that the search giant dearly wanted, it moved on to Plan B and contacted Motorola to see what it had for sale. Less than six weeks later, Google's blockbuster acquisition came together -- but only after Google raised its purchase price. Twice.
In a regulatory filing submitted Tuesday, Motorola Mobility breaks down in startling detail the timeline and milestones of Google's $12.5 billion takeover deal. Patents were what originally piqued Google's interest because it wants to arm up for Silicon Valley's ongoing patent war. But it didn't take long for Google to come around to Motorola's view that if Google wanted the patents, it should buy the whole company.
After a month-long series of meetings among the two companies' top executives -- initiated by Andy Rubin, Google's senior vice president of mobile -- Google decided to make its move on Aug. 1. It sent Motorola an acquisition offer for $30 a share.
Four days later, Motorola rejected that bid and suggested Google open its wallet a bit further. Google obligated: It came back on Aug. 9 offering $37 per share.
But in a sign of just how badly and how quickly Google wanted this deal done, it raised its offer again later that same day. After Motorola CEO Sanjay Jha told Google he would back a slightly higher proposed price, Google upped its all-cash offer to $40 a share -- kicking in an extra $3 billion over its initial bid even though Motorola was not in talks with any other potential buyers.
Google (GOOG, Fortune 500) told Motorola it wanted an answer within 24 hours. This time, Motorola (MMI) said yes. After a week of hammering out the fine print, the two companies stuck a final deal the morning of Aug. 15, and fired off their press release soon after.
Throughout the discussions, Motorola's board stayed in touch with Carl Icahn, a famously hands-on shareholder who owned 11% of Motorola Mobility's stock. He was sniffing around for a deal: In late July, he sent Motorola a letter suggesting it shop around its patent portfolio. Once Google's takeover bid hit $40 a share, Icahn threw his support behind it.
Motorola took advantage of Google's eagerness to extract some additional deal-sweeteners, including the steep $2.5 billion breakup fee Google will owe Motorola if it can't get antitrust clearances.
That regulatory review is ongoing. 
