Mexico–Republic of Texas relations

Foreign relations between Mexico and the Republic of Texas were unofficially initiated in 1836 at the signing of the Treaties of Velasco, which de facto declared Texas independent from Mexico, though the Mexican Government never fully recognized Texas' Independence. The relations between the two countries, however hostile, continued until 1845 after the annexation of Texas by the United States, and the beginning of the Mexican–American War.

Source: Wikipedia — Mexico–Republic of Texas relations (CC BY-SA 4.0)