Siete Leyes in the context of "Alta California"

Antonio de Padua María Severino López de Santa Anna y Pérez de Lebrón (21 February 1794 – 21 June 1876), often known as Santa Anna, was a Mexican general, politician, and caudillo who served as the 8th president of Mexico on multiple occasions between 1833 and 1855. He also served as vice president of Mexico from 1837 to 1839. He was a controversial and pivotal figure in Mexican politics during the 19th century, to the point that he has been called an "uncrowned monarch", and historians often refer to the three decades after Mexican independence as the "Age of Santa Anna".

Santa Anna was in charge of the garrison at Veracruz at the time Mexico won independence in 1821. He would go on to play a notable role in the fall of the First Mexican Empire, the fall of the First Mexican Republic, the promulgation of the Constitution of 1835, the establishment of the Centralist Republic of Mexico, the Texas Revolution, the Pastry War, the promulgation of the Constitution of 1843, and the Mexican–American War. He became well known in the United States due to his role in the Texas Revolution and in the Mexican–American War.

The Centralist Republic of Mexico (Spanish: República Centralista de México), or in the anglophone scholarship, the Central Republic, officially the Mexican Republic (Spanish: República Mexicana), was a unitary political regime established in Mexico on 23 October 1835, under a new constitution known as the Siete Leyes (lit. 'seven laws') after conservatives repealed the federalist Constitution of 1824 and ended the First Mexican Republic. It would ultimately last until 1846, when the Constitution of 1824 was restored at the beginning of the Mexican–American War.

Two presidents would predominate throughout this era: Santa Anna and Anastasio Bustamante.

The Republic of Texas (Spanish: República de Tejas), or simply Texas, was a sovereign country in North America from March 2, 1836, to February 19, 1846. Texas was bordered by Mexico to the west and southwest, the Gulf of Mexico to the southeast, the two U.S. states of Louisiana and Arkansas to the east and northeast, and U.S. unorganized territory encompassing parts of the current U.S. states of Oklahoma, Kansas, Colorado, and Wyoming to the north. The Texas Revolution began when hostilities broke out on October 2, 1835, shortly before the regime of Mexican President and General Antonio López de Santa Anna adopted a new Mexican constitution known as the Siete Leyes that abolished the authority of the states under the federal republic and established a centralized government. The revolution lasted for over six months. On March 2, 1836, delegates in convention proclaimed the Texas Declaration of Independence. Major fighting ended on April 21, 1836, with the Treaties of Velasco that ended the fighting and secured Texas' independence.

The Mexican Congress refused to recognize the independence of the Republic of Texas, as the Treaties of Velasco were signed by Santa Anna under duress as prisoner. The majority of the Mexican Congress did not approve the agreement. Much of its territory was controlled and disputed by Mexico or the Comancheria; Mexico considered it a rebellious province during its entire existence. The Anglo-American residents of the area and of the republic were referred to as Texians, while Texans of Mexican descent were referred to as Tejanos.

The office of the vice president of Mexico was first created by the Constitution of 1824, then it was abolished in 1836 by the Seven Constitutional Laws, then briefly restored in 1846 following the restoration of the Constitution of 1824 and lasted a year until 1847 where it was again abolished through a constitutional amendment, it was later restored in 1904 through an amendment to the Constitution of 1857, before being finally abolished by the current Constitution of 1917. Many Mexican vice presidents acted as president during time between the end of the First Mexican Empire and the establishment of the Second Mexican Empire.

Bases Orgánicas (English: Organic Bases) was the name given to the constitution of Mexico which came into effect in 1843. It was the second and final constitution attempted during the Centralist Republic of Mexico, after the Siete Leyes.

National instability had resulted in a coup which overthrew the presidency of Anastasio Bustamante at the end of 1841. The coup plotters led by Santa Anna had proclaimed the need for a new constitution, and held elections for a new constitutional congress. The newly elected congress however was not to the government's liking and it was subsequently dissolved in a self-coup at the end of 1842. A new government appointed a Council (Junta) of Notables that produced a new constitution on 12 June 1843.

The Head of State of Mexico is the person who controls the executive power in the country. Under the current constitution, this responsibility lies with the President of the United Mexican States, who is head of the supreme executive power of the Mexican Union. Throughout its history, Mexico has had several forms of government. Under the federal constitutions, the title of President was the same as the current one. Under the Seven Laws (centralist), the chief executive was named President of the Republic. In addition, there have been two periods of monarchical rule, during which the executive was controlled by the Emperor of Mexico.

The chronology of the heads of state of Mexico is complicated due to the country's political instability during most of the nineteenth century and early decades of the twentieth century. With few exceptions, most of the Mexican presidents elected during this period did not complete their terms. Until the presidency of Lázaro Cárdenas, each president remained in office an average of fifteen months.