According to Brian Baldinger from the NFL Network, in order to be a dynasty, teams need to have a few things.
Elite level defense
The Ravens defense has been the standard of NFL play since the early 2000s. With big time players like Ed Reed, Ray Lewis, Haloti Ngata, C.J. Mosley, Jimmy Smith, Lardarius Webb, and so many others, Baltimore's defense has no shortage of star players. Consistently a top 10 defense despite multiple defensive coaching changes over the last decade and a half, the Ravens have just been one of the NFL's best for so long.
Franchise QB play
With the season bearing ever closer, we've had many discussions about the merits of Joe Flacco. For this though, the criteria is that the team has to have a franchise, championship caliber quarterback. That is Joe Flacco. A higher number of wins in the playoffs since 2008 than any other quarterback in the NFL, Flacco has done it at home, on the road and all the way through the SuperBowl, winning an MVP in the process. Regardless of if Flacco is "elite", he sure as hell fits the criteria put in front of us for a dynasty.
A head coach that has a vision that is executed
Say what you will about head coach John Harbaugh. I don't much like his Xs and Os knowledge and I don't feel too great about his red flag challenges, but the man wins. He brought into Baltimore a system of hard work and accountability that was much needed after the softer days of Brian Billick. With the term "play like a Raven" coming around, players bought into Harbaugh's system of no nonsense, hard-nosed football and we've seen an unprecedented level of success for Baltimore.
So with that criteria, Baltimore has absolutely been a dynasty. Multiple Super Bowl victories to go with the three major points that Baldinger made should go to show that Baltimore is one of the few elite teams in the NFL.