Christian Ahlmann began riding at the age of 11. He made his international debut in 1988, winning silver at the German Junior Championships that same year. He would go on to win the gold medal just two years later.

Between 1993 and 1995, he was a consistent performer in the Young Riders category, notching up a total of six medals at the German and European Championships. He was soon called up to the Seniors, where his career really took off with Cöster, a new arrival at his stables. The stallion carried him to a sequence of achievements, including individual and team gold at the European Championships in 2003, team gold at the European Championships in 2005, a bronze medal at the 2006 World Championships, team silver at the 2007 European Championships and a bronze medal at the 2004 Olympics...

In 2009, Cöster was followed by Taloubet Z, a stallion owned by his partner, international Belgian rider Judy-Ann Melchior. In 2011, he rode Taloubet Z to victory in the World Cup final. In 2012, after a fine season, the German rider was selected for the London Olympics, where he finished 10th in the team competition. In 2013 with Codex One, his other Grand Prix horse, he wins team silver at the European championship 2013and the mythical win in THE Grand Prix of Aachen in 2014.