Lyncker was born in Spandau, Prussia into a military family, with his father, his father-in-law and two brothers being officers. He took part in the Franco-Prussian War of 1870-71, and two of his sons died in the First World War. He has been evaluated as "politically innocent, intellectually mediocre, with subservient devotion to Wilhelm II." By 10 August 1914 he was considering replacing Helmuth von Moltke with Erich von Falkenhayn as Chief of the German General Staff. After the failure of the Battle of the Marne it was his duty to convince von Moltke to leave. He died in Demnitz, Germany.