AT&T's $85.4-billion bid to buy Time Warner is now official, facing what's expected to be a tough regulatory review, given the reach and impact of the telecom and the media behemoths.

The deal is a large one for both spaces, though each has seen a fair amount of reshuffling in the power rankings over the years. (In fact, both AT&T and Time Warner are themselves results of consolidation and spin-offs.)

The latest in this year's leadup was Verizon's bid to buy Yahoo to combine its Internet assets with the telco's earlier purchase of AOL. It's a race to reach as many users — and advertisers — with as much content as possible.

Below is a condensed history.

1877

AT&T's ancestor is born as Bell Telephone Company. Note quite a decade later, the American Telephone and Telegraph Company was formed as a subsidiary to create a long-distance network.

1923

Time magazine debuts on March 3.

Four Warner brothers establish Warner Brothers Pictures, which in 1969 becomes a subsidiary of Warner Communications, created when Kinney National Services buys what by then is Warner Brothers-Seven Arts Inc.

1984

The monopoly Bell System, aka Ma Bell, splits up into eight companies, dubbed Baby Bells, after the Justice Department pursues an antitrust case. Decades later, parts of those companies were eventually subsumed by modern-day AT&T, Verizon and CenturyLink.

1989

Time Inc. and Warner Communications announce a merger to create Time Warner Inc., described by The New York Times as the "largest media and entertainment conglomerate in the world" and valued at more than $15 billion.

1995

Time Warner and Turner Broadcasting System announce a $7.5-billion merger, uniting brands including CNN, Time magazine, Warner Brothers and the Cartoon Network.

The Walt Disney Company says it will buy Capital Cities/ABC Inc. for $19 billion, creating what The New York Times once again describes as " the world's most powerful media and entertainment company."

2000

AOL announces its plan to buy Time Warner for more than $160 billion, at the peak of the dot-com boom.

2004

Comcast drops its bid to buy Disney for $54 billion after a rebuff.

2005

SBC Corporation — formerly known as one of the Baby Bells, Southwestern Bell Corporation — acquires AT&T for more than $16 billion, creating the telecom company we now know under that brand.

2008

Time Warner spins off its cable unit, which becomes Time Warner Cable.

2009

Time Warner spins off AOL, marking the end of what goes down in history as one of the most disastrous mergers.

2011

Comcast receives regulatory approval for its $30-billion bid to buy a majority stake in NBC Universal. Comcast completely took over NBC Universal in 2013, when GE divested its stake.

AT&T gives up on its $39-billion attempt to buy T-Mobile after the Justice Department and the Federal Communications Commission stage forceful opposition to the union of the No. 2 and No. 4 wireless carriers.

2013

Time Warner spins off its Time Inc magazine division.

2014

Verizon buys out Vodafone's stake in Verizon Wireless for $130 billion, gaining full ownership of the nation's largest wireless carrier.

Time Warner spurns a bid from Twenty-First Century Fox, reported at $80 billion.

2015

Comcast abandons its $45-billion bid to buy Time Warner Cable after the FCC opposes the merger over concerns of creating a cable operator and Internet provider with too much control over what Americans watch and do online.

Verizon buys AOL for $4.4 billion.

AT&T gets government approval to buy satellite TV company DirecTV for $48.5 billion, creating one of the largest pay-TV providers to compete with Comcast.

2016

The FCC and DOJ approve the $88-billion merger of Charter Communications with Time Warner Cable and a smaller rival Bright House Networks, creating the second-largest broadband provider and the third-largest video provider.

Comcast buys DreamWorks Animation for $3.8 billion to compete against Disney.

Time Warner buys a 10-percent stake in Hulu for $583 million.

Verizon and Yahoo announce a $4.8-billion merger that would give Verizon ownership of Yahoo's Internet assets.

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