For the most part, the core of the team, and no better word to define it than that, has stayed together. A few players have left, and some have entered but the team managed to overcome adversity, and well, become a dynasty. Championship teams appear often, but rarely can they achieve the amount of success over an amount of time like the Spurs have. You ask how this team became a dynasty.
David Robinson joined the Spurs in the 1989-1990 NBA season. A quick improvement was made upon Robinson's arrival, but still San Antonio could not be considered a championship contender yet. Anyway, Michael Jordan and the Bulls were in the process of dominating the entire league.
Luck determined the franchise's great future, when the Spurs received the #1 pick in the 1997 NBA Draft, due to some help from the draft lottery. Tim Duncan was the obvious selection, and ever since his arrival in San Antonio, the Spurs have been an elite team.
After the '98 season, Michael was finally gone. As a result, in the 1998-1999 season the Spurs were expected to contend for a title. However, those aspirations were put on hold as David Stern locked out the players in order to force a new collective bargaining agreement with the NBA Players Association. Luck struck again, as the lockout ended and the Spurs finished the shortened season with a 37-13 record. The team was just as dominant in the playoffs, rolling through the Western Conference with a record of 11-1. Fast work was made of the New York Knicks, and the Spurs had captured their first championship. But one proved not to be enough.
In the time between championships the Spurs acquired two key players, Tony Parker and Manu Ginobili. These two foreign stars have a played a huge part in leading San Antonio to their last three titles. 2003, 2005, and now, 2007.
A few years passed, and another great team arrived as the Los Angeles Lakers won three straight championships. However, in 2003 the title was back for the taking, and that is exactly what the Spurs did. The dream ending was set up as David Robinson announced that the season would be his last. Robinson went out with a bang as the Spurs defeated the New Jersey Nets in the Finals.
In the 2006-07 season, the Spurs finished with a 58-24 record and a number 3 seed in the playoffs. Quick work was made of the Denver Nuggets, Phoenix Suns, and Utah Jazz. In the 2007 NBA Finals, they swept the Cleveland Cavaliers and captured their fourth title in 9 years, tentatively securing their place in history as an NBA dynasty.
To some people, this dynasty talk is debatable, but not in my mind. The Spurs have dominated the league for a while, and have the rings to prove it. Dynasty and destiny fulfilled.
Winning has become a common occurrence in Spur country, and do not expect that streak to end anytime soon. Celebrate all you want San Antonio fans, because right now you are on top of the sports world.