Short answers, pulled from the story.
Microsoft transitioned its internal Games Group into a wholly separate division named Microsoft Games in March 2000. This move coincided with the public announcement of the first Xbox console.
Phil Spencer was named the new head of Microsoft Studios to replace Jason Holtman under Satya Nadella's direction. Spencer began looking for ways to expand Microsoft Studios to make it profitable and started negotiations for acquiring Mojang in late 2014.
The total price reached $8.1 billion when the acquisition of ZeniMax Media was formally completed on the 9th of March 2021. Both U.S. and European Union regulatory agencies approved the acquisition by early March 2021.
Microsoft shut down Lionhead's Fable Legends and Press Play's Project Knoxville in March 2016. Changes to the Microsoft Studios website indicated further closures including BigPark, Good Science Studio, Leap Experience Pioneers, Function Studios, and State of the Art.
On the 6th of October 2024, 343 Industries officially announced their rebranding as Halo Studios confirming multiple Halo games were in development using Unreal Engine 5 instead of proprietary Slipspace Engine.