BERLIN—Germany has reached an agreement with Namibia that will see it officially recognize as genocide the colonial-era killings of tens of thousands of people and commit to spending a total of €1.1 billion ($1.3 billion), largely on development projects. The accord announced Friday is the result of more than five years of talks with Namibia on the events of 1904–1908, when Germany was the southern African country’s colonial ruler. Historians say German Gen. Lothar von Trotha, who was sent to what was then German South West Africa to put down an uprising by the Herero people in 1904, instructed his troops to wipe out the entire tribe. They say that about 65,000 Herero were killed and at least 10,000 Nama. “In the light of Germany’s historical and moral responsibility, we will ask Namibia and the descendants of the victims for forgiveness,” German Foreign Minister Heiko Maas said in a statement. …