How did Elizabeth I come to be queen of England?

 Queen Elizabeth I’s right to the throne wasn’t always guaranteed. Her father, King Henry VIII, had Parliament annul his marriage to Elizabeth’s mother—his second wife, Anne Boleyn—thus making Elizabeth an illegitimate child and removing her from the line of succession (although a later parliamentary act would return her to it).

https://www.britannica.com/story/how-did-elizabeth-i-come-to-be-queen-of-england#:~:text=Her%20father%2C%20King%20Henry%20VIII,would%20return%20her%20to%20it).