Three of my four published biographies were the first ones about their subject. (The other book was the first to focus on the woman's life rather than only on her marriage to a famous fellow artist.) Perhaps because reviewers are frequently not biographers themselves, I have found that they—and other readers—fail to understand what's involved in making a maiden voyage as a biographer.
Many biographies published today are about someone famous who usually has been the subject of multiple books. Because previous biographers bave established the chronology and the facts (as each writer perceived them), the new biographer is free to write in a more experimental way. She can choose to deal only with a certain period of time in the person's life, quarrel with information presented in other books, present a new theory, focus on the work at the expense of the life, or experiment with style.
First biographies about people who are not widely known are obliged to hew more closely to the pattern of "traditional" biography. A responsible biographer presenting a subject to the world for the first time must cover the entire stretch of that life in a way that presupposes no prior knowledge on the part of the reader. The first biographer strives to present the subject as completely, truthfully, and seriously as possible, with the fullest possible awareness of the standards and mores of her era.
This means restraining the impulse to add fanciful suppositions or strained attempts to be "relevant." It means not writing in a style intended to imitate or compete with the cleverness of the subject, and not allowing a theoretical construct to overshadow the narrative of the life.
For these reasons, a first biography may strike members of the coterie already familiar with the subject to contain too many quotidian facts at the expense of theoretical commentary and witty asides. Yet there is still plenty of room for elegant writing, thoughtful conclusions, and the kind of precise descriptions and well-chosen quotations that make the subject come to life for the reader.