After their defeat to the Russians in the Russo-Turkish War (1828–1829), the Ottoman Empire restored the Danube ports of Turnu, Giurgiu and Braila to Wallachia, and agreed to give up their commercial monopoly and recognize freedom of navigation on the Danube as specified in the Treaty of Adrianople, which was signed in 1829. The political autonomy of the Romanian principalities grew as their rulers were elected for life by a Community Assembly consisting of boyars, a method used to reduce political instability and Ottoman interventions. Following the war, Romanian lands came under Russian occupation under the governance of General Pavel Kiselyov until 1844. During his rule, the local boyars enacted the first Romanian constitution.