Roberto Carlos joined Real Madrid in the year 1996 close season, where he was given the number 3 shirt and held the position as the team's first choice left-back from the 1996-97 season until the 2006-07 season. During his 11 seasons with Madrid, he appeared in 584 matches in all competitions, scoring 71 goals. He is Real Madrid's most capped foreign-born player in La Liga with 370 appearances, after breaking the previous record of 329 held by Alfredo Di Stefano in January 2006. During his Real Madrid career, Roberto Carlos was, alongside Milan and Italy legend Paolo Maldini, considered the greatest left-back in the world. As a high-profile player and one of the most influential members of the team, Roberto Carlos was considered one of Madrid's Galacticos during Florentino Perez's first tenure as club president.  He won four La Liga titles with Madrid, and played in the 1998, 2000 and 2002 UEFA Champions League finals, assisting Zinedine Zidane's winning goal in 2002, considered one of the greatest goals in Champions League history. Roberto Carlos was named as Club Defender of the Year and included in the UEFA Team of the Year in 2002 and 2003. In the later part of his Real Madrid career, Carlos was named as one of the club's "three captains" alongside Raul and Guti. Renowned for getting forward from his left-back position and scoring spectacular goals, in February 1998, he scored arguably his most memorable goal for Real Madrid with a bending volley struck with the outside of his left foot from near the sideline in a Copa del Rey match against Tenerife in what was described as an "impossible goal".  On the final day of the 2002-03 season, with Madrid needing to beat Athletic Bilbao to overtake Real Sociedad and win their 29th La Liga title, Carlos scored from a free-kick in the second minute of first half stoppage time to put los Blancos 2-1 ahead. The team eventually ran out 3-1 winners to wrap up the title. On 6 December 2003, Roberto Carlos scored the opening goal for Madrid as they beat Barcelona in El Clasico at Camp Nou for the first time in a La Liga match in 20 years.  In March 2007, in the second leg of the Champions League round of 16 against Bayern Munich, Roberto Carlos failed to control the backpass when Madrid kicked off, allowing Bayern's Hasan Salihamidzic to steal the ball and feed to Roy Makaay, who scored the quickest goal in Champions League history at 10.12 seconds. Roberto Carlos bore the brunt of criticism for that mistake which led to the team's elimination from the Champions League, and, on 9 March 2007, he announced he would leave Real Madrid upon the expiration of his contract at the end of the 2006-07 season. His final goal for Real Madrid was a stoppage time winner against Recreativo de Huelva with three games remaining in the 2006-07 La Liga season. The goal proved to be crucial to Real Madrid winning its 30th league title as they eventually finished level on points with Barcelona, becoming champions via the head-to-head rule. Madrid clinched La Liga in Roberto Carlos' final match, a 3-1 win over Mallorca at the Santiago Bernabeu Stadium.

Answer this question "When did he join Real Madrid?" by extracting the answer from the text above.
Roberto Carlos joined Real Madrid in the year 1996 close season, where he was given the number 3 shirt