There's a biography of Jaan Kross written in Finnish and translated into Estonian. This is, of course, frustrating for those who would like to get more of an overview as to who this author was and what he wrote, but don't read those two relatively obscure languages. But I presume that it will gradually appear in French, German, Spanish and even English. One day.
This biography was originally publishing in Finland in 2008, because the author is a Finn, Juhani Salokannel, who has worked, for instance, as the head of the Finnish Institute in Tallinn. Strangely enough, this book appears to be the first full biography of Kross and, more especially, the first detailed bibliographical survey of what Kross has written, describing the books and their context. What is strange is that although Kross is regarded as perhaps the greatest postwar Estonian author during the latter half ot the 20th century, no Estonian seems to have written a book if such a scope as that of Salokannel (some 500 pages).
An interesting aspect of the book is that Salokannel uses the chronology of the centuries and decades that Kross' various novels were set in to move forward from those set in the 16th century right up to the 20th century. So about 280 of the 500 pages describe the 15 or so books in detail moving forward from the late Middle Ages via then eighteenth and 19th centuriess to the period where some of Kross' novels become semi-autobiographical. The rest covers Kross' life and other matters placing them in the context of the troubled 20th century history of Estonia.