In the months leading up to Microsoft’s acquisition of Nokia’s phone business, the two companies approached Shoreditch-based media company TCOLondon to secretly build a unique book for the nearly 20,000 Nokia employees set to join Microsoft. The 128-page book was edited and illustrated in London before being printed and shipped to employees in more than 90 cities in 53 countries.

It’s a celebration of the rich history that Nokia and Microsoft both share, including etchings of Nokia’s origins in a paper mill in Finland and Microsoft’s roots in New Mexico. Illustrations range from the first-ever GSM call to surgeons using the Kinect sensor for operations. Nokia and Microsoft approached TCOLondon in mid-December, with the original plan to have the book ready and finished for February 1st. A later-than-expected acquisition meant the book was delivered to employees at the deal closure in late April. Microsoft CEO Satya Nadella even visited Finland to present a copy of the “One” book to Finnish President Sauli Niinisto. Here are some of the many illustrations inside the 128 pages.