This article is written in memory of Judge Carl-August Fleischhauer, who died on 4 September 2005, aged 74, during the first year of his retirement after a long and rewarding career in the service of both his native country Germany and the United Nations. The first part of the article sketches Judge Fleischhauer's background and career before being elected to the International Court of Justice, the second part describes his contributions to the work of the Court, and in the last part the authors reflect on the significance of Judge Fleischhauer's contributions to international law.