By 1353, the three original cantons had joined with the cantons of Glarus and Zug and the Lucerne, Zürich and Bern city states to form the "Old Confederacy" of eight states that existed until the end of the 15th century. The expansion led to increased power and wealth for the federation. By 1460, the confederates controlled most of the territory south and west of the Rhine to the Alps and the Jura mountains, particularly after victories against the Habsburgs (Battle of Sempach, Battle of Näfels), over Charles the Bold of Burgundy during the 1470s, and the success of the Swiss mercenaries. The Swiss victory in the Swabian War against the Swabian League of Emperor Maximilian I in 1499 amounted to de facto independence within the Holy Roman Empire.
Try to answer this question if possible (otherwise reply "unanswerable"): Which Swiss victory in 1499 amounted to de facto independence within the Holy Roman Empire?
Swabian War