SHARK ISLAND, Namibia—Just over a century ago, Germany built one of its first concentration camps on a narrow peninsula jutting into the Atlantic.

A 1904 uprising in what was then called German South-West Africa turned into a war of annihilation against the Herero and Nama peoples. At least 60,000 are believed to have died, including some 2,000 in the Shark Island camp, where inmates were starved, beaten and worked to death.

That episode of colonial brutality, considered by many historians to be the first genocide of the 20th century, is now testing the limits of historical apologies.

Namibia says it wants Germany to officially recognize that its actions constituted genocide, to issue a formal apology and to pay reparations. Berlin says it is willing to meet the first two demands and to pay some form of compensation. The two countries have been negotiating for more than a year.

Other governments have expressed regret or sorrow for past atrocities. What makes the current situation novel is that most have stopped short of any official apology, and financial payments have been rare.