WASHINGTON (Reuters) - Microsoft Corp MSFT.O has won the U.S. Pentagon's $10 billion cloud-computing contract, the Defense Department said on Friday, beating out favorite Amazon.com Inc AMZN.O.

FILE PHOTO: The Microsoft logo is pictured ahead of the Mobile World Congress in Barcelona, Spain February 24, 2019. REUTERS/Sergio Perez/File Photo

The contract, called the Joint Enterprise Defense Infrastructure Cloud, or JEDI, is part of a broad modernization of the Pentagon’s information technology systems.

Here is a timeline of important dates leading up to the award:

JULY 26, 2018: The Pentagon released the final request for proposals from competitors, seeking a single winner to allow for the most rapid adoption of the technology. It said the deal’s initial two-year period would provide time to ensure JEDI was up to standards, noting that new contractors would be needed for other cloud computing demands in the future. The contract, valued at $10 billion over 10 years, was set to be awarded in September.

AUGUST 6, 2018: Oracle Corp ORCL.N filed a protest with the DOD over its plans to award the contract to a single company instead of allowing for multiple winners, arguing that the Pentagon would be locked into a legacy contract for a decade or more. DOD's Government Accountability Office had until November to respond.

OCTOBER 8, 2018: Alphabet Inc's GOOGL.O Google said it was no longer vying for the $10 billion cloud computing contract with the DOD, in part because the company's new ethical guidelines did not align with the project, without elaborating.

OCTOBER 9, 2018: Microsoft said its expanded Azure cloud service to help government clients save data on their own servers would be available by the end of the first quarter of 2019, as it battled Amazon.com for the contract.

NOVEMBER 14, 2018: The Government Accountability Office denied the protest filed by Oracle, finding that the agency “reasonably” determined that the single-award approach was in the government’s best interests for reasons including national security concerns and complied with applicable law.

APRIL 26, 2019: Amazon.com Inc and Microsoft Corp were selected to continue competing for Pentagon cloud-computing services as part of a contract that could be worth some $10 billion.

The selection left Oracle and IBM Corp IBM.N out of the competition for the contract, which is part of a broad modernization of Pentagon information technology systems.

JULY 18, 2019: U.S. President Donald Trump said his administration was looking closely at Amazon.com’s bid on a $10 billion cloud contract with the DOD after getting complaints from other technology companies.

JULY 19, 2019: Four Republican members of U.S. Congress, including House Armed Services Committee ranking member Mac Thornberry, sent a letter to Trump urging him to move forward with a $10 billion cloud contract with the DOD.

AUGUST 1, 2019: The Pentagon decided to put on hold its decision to award the $10 billion cloud-computing contract after Trump said his administration was examining Amazon.com Inc’s bid following complaints from other technology companies.

AUGUST 5, 2019: Democratic Senators Mark Warner and Jack Reed asked U.S. Defense Secretary Mark Esper if “outside” influence caused him to delay awarding a $10 billion cloud-computing contract, after Trump suggested Amazon.com Inc should not win it.

OCTOBER 22, 2019: U.S. Defense Secretary Mark Esper removed himself from reviewing a disputed $10 billion cloud-computing contract because of a possible conflict of interest.