The future Buddha, Siddhartha Gautama, was born in the fifth or sixth century B.C. in Lumbini (in modern-day Nepal). Siddhartha is a Sanskrit name meaning "one who has accomplished a goal," and Gautama is a family name.
His father, King Suddhodana, was the leader of a large clan called the Shakya (or Sakya). It's not clear from the earliest texts whether he was a hereditary king or more of a tribal chief. It is also possible that he was elected to this status.
Suddhodana married two sisters, Maya and Pajapati Gotami. They are said to have been princesses of another clan, the Koliya, from what is northern India today. Maya was the mother of Siddhartha, and he was her only child. She died shortly after his birth. Pajapati, who later became the first Buddhist nun, raised Siddhartha as her own.
By all accounts, Prince Siddhartha and his family were of the Kshatriya caste of warriors and nobles. Among Siddhartha's more well-known relatives was his cousin Ananda, the son of his father's brother. Ananda would later become the Buddha's disciple and personal attendant. He would have been considerably younger than Siddhartha, however, and they didn't know each other as children.