So Mike Martz is officially gone. An exciting, successful and often perplexing era of Rams football has ended.

The “Greatest Show on Turf” has been cancelled, after producing two NFC Championships, a Super Bowl championship and regular trips to postseason play.

Mad Mike will be sorely missed. Pro football isn’t going to be nearly as interesting in his absence, on many levels. Ingenious, quirky, unconventional, brazen, bizarre . . . many adjectives describe his tenure as offensive coordinator, then head coach of the Rams.

We were all fortunate to be a part of it -– fans, media types, players, staffers at Rams Park, everybody. It was a heck of a ride.

But it’s over. The inevitable occurred Monday, when Martz was officially terminated. Now the franchise looks forward.

Now the onus falls on Georgia Frontiere, Stan Kroenke, John Shaw, Jay Zygmunt and Charley Armey to build a new era. They must find the right head coach, somebody capable of rebuilding the Rams defense while maintaining an explosive offense.

The New Regime must hire a great coaching staff, with strong defensive and offensive coordinators. The New Regime must blend the existing talent, which is still significant, with the right draft picks and the right free agents to build a winner.

The New Regime must build an excellent football operation, top to bottom, and keep all the coaches and executives on the same page.

Martz set a high bar for his successor. The Rams have been a marquee team since 1999. Even when decimated by injuries, the Rams remained a formidable opponent.

He overhauled the entire defense once, then won a conference championship. He changed quarterbacks and won a division title. He guided two injury-riddled teams into the playoffs through the back door, perhaps his most significant achievement.

Fans wanted more, of course. They wanted trips to the Super Bowl every year. They believe the Rams would have been the New England Patriots of their time, had Dick Vermeil remained head coach.

(We’ll never know how much more Vermeil would have gotten from this team, but Vermeil’s inability to get the Kansas City Chiefs over the hump reminds us how difficult it is to succeed in the NFL.)

Monday’s firing finished the debate on how good Martz really was or how much more he could have done. He’s gone. His record is what it is.

Now the New Regime will get its shot at doing better.

The pressure on Shaw is considerable. His performance as an NFL executive is mixed, at best. He and Zygmunt were Architects of Doom in the 1990s, killing pro football in Southern California with an awful product and then bringing that slop to St. Louis.

In 1990, the Rams were 5-11. Then they went 3-13, 6-10, 5-11, 4-12, 7-9, 6-10, 5-11 and 4-12 over the next eight years.

It is difficult in the parity-driven NFL to remain awful for that stretch of time. The Rams employed four different coaches during that span and they all failed. The one constant was Shaw. His record spoke for itself during the 1990s.

Nobody was worse.

Finally, in 1999, Rams executives made all the right moves. Shaw convinced Vermeil to change up the offense. He hired Martz as his new coordinator and the team acquired Trent Green, Marshall Faulk and Torry Holt.

We know what happened next. Now we are all wondering, can it happen again?

Will Shaw and Co. make all the right moves? Will the Rams hire the right coach, build the right staff, overhaul the defense and maintain a cutting-edge offense with Holt, Marc Bulger, Steven Jackson, Isaac Bruce, Kevin Curtis and Shaun McDonald?

The opportunity exists to rebuild quickly. As we saw Sunday night, there are some significant pieces to build around.

Leonard Little, when motivated, is one of the league’s most disruptive defensive players. There is still some hope for fellow defensive end Anthony Hargrove. Linebacker Pisa Tinoisamoa wants to play football.

Some of the kid defensive backs looked eager to compete. The Rams may not stink at cornerback if Jerametrius Butler and Travis Fisher get healthy and Ron Bartell keeps improving.

A hard-hitting safety and a powerful linebacker could change the personality of this defense, as long as the next coordinator can weed out the dogs and create an aggressive unit mentality.

On offense, the Rams must replace right guard Adam Timmerman and continue developing tackle Alex Barron and interior linemen Claude Terrell and Richie Incognito. The receivers, running backs and quarterbacks are fine.

This football team needs better focus and an overall sense of purpose. It needs leadership -– in the front office, the coaching staff and locker room -– that will not accept sloppiness and underachievement.

The Rams must commit to becoming sound across the board, in all phases of the football operation. Only then can the team make the most of its still-considerable talent.

Absentee management isn’t going to get it done. If Shaw isn’t willing to run this franchise 24/7 in St. Louis, then he should hire somebody who will. If he isn’t up to the job, he should move back to Los Angeles and become Frontiere’s emissary and advisor.

The general manager should be the general manager, making the calls on college AND pro personnel. The salary cap specialist should tend to the cap and not pretend he’s Vince Lombardi. The head coach should coach and the coordinators should coordinate.

Running a pro sports franchise is difficult. When the president, president of football operations, general manager and head coach can’t work together, doing what they do best, then the task becomes nearly impossible.

Shaw and Co. should expect a lot from the next head coach. And the next head coach should expect a lot from Shaw and Co.

Creating a New Regime involves far more than hiring a new coach and a new staff. It demands a new commitment from everybody at Rams Park to do everything the right way.

Let the change begin.