The Texas state flag is the 1839 National flag of the Republic of Texas featuring the famous Lone Star. The red, white, and blue of the Texas state flag represent bravery, purity and loyalty.

Six different flags have flown over Texas representing the countries which have ruled it - France, Spain, Mexico, the Republic of Texas, the Confederate States of America, and the United States of America. Texans proudly wave all six official flags for public displays and expositions.

Source:

Historic Flags: Texas State Library

Links:

Six National Flags Flown over Texas: U of Texas Library
Flags of Texas: Handbook of Texas
6 Flags of Texas: Texas Almanac
6 Flags of Texas: Texas State Library
6 National Flags of Texas: Lone Star Junction
State Flags - 50 states List
National Flag