Ignoring the reservations of the foreign ministry, the French authorities in Tonkin attempted to enforce the Harmand Treaty during the autumn of 1883, but with little success. The Vietnamese paid only lip service to the treaty's provisions. Prince Hoàng Kế Viêm continued to garrison Sơn Tây with a large Vietnamese army, in contravention of Article 4 of the treaty, and the civil authorities cooperated with the French only grudgingly. The court at Huế only modified its recalcitrant attitude after Admiral Courbet inflicted a decisive defeat on Liu Yung-fu and Hoang Ke Viem at Sơn Tây in December 1883. Believing that further resistance was useless, the court at Huế now ordered the civil authorities in Tonkin to collaborate with the French.