Biographical facts about Jane Austen are "famously scarce" (few). Only a few letters remain (it is estimated that only 160 out of Austen's 3,000 letters survive). Her sister Cassandra (to whom most of the letters were written) burned "the greater part" of the ones she kept. The letters she did not destroy she censored. Other letters were destroyed by the heirs of Admiral Francis Austen, Jane's brother. Most of the biographies written about her for 50 years after she died was by her relatives, who often described her as "good quiet Aunt Jane". Scholars have not been able to find much information after that.