Until roughly 1490, the Swiss had a virtual monopoly on pike-armed mercenary service. However, after that date, the Swiss mercenaries were increasingly supplanted by imitators, chiefly the "Landsknechts". Landsknechts were Germans (at first largely from Swabia) and became proficient at Swiss tactics, even surpassing them with their usage of the "Zweihänder" to crush opposing pike formations. This produced a force that filled the ranks of European armies with mercenary regiments for decades. After 1515 the Swiss pledged themselves to neutrality, other than regarding Swiss soldiers serving in the ranks of the Royal French army. The "Landsknecht", however, would continue to serve any paymaster, even, at times, enemies of the Holy Roman Emperor (and "Landsknechts" at times even fought each other on the battlefield). The "Landsknecht" often assumed the multi-coloured and striped clothing of the Swiss.