How did William 1 remove the threat of the troops at Dover?

William I removed the threat of the troops at Dover by strategically fortifying the area and establishing control over the port. He built a strong castle to assert his authority and deter any potential rebellions. Additionally, he ensured loyalty among local leaders and implemented measures to secure his rule in the region, effectively neutralizing any military threats. This consolidation of power helped stabilize his reign following the Norman Conquest.