The text mentions that writing biographies of great men like politicians or warriors is a form of worldly Guru service. Can you provide the biography of one such politician mentioned in the book?

The preface to the Shri Sai Satcharita does not provide a biography for any specific politician or warrior. In Chapter 0, the author mentions figures like 'unique politicians' and 'state-founding brave warriors' only as examples to illustrate a category of 'worldly Gurus.' The text's main purpose in bringing them up is to create a contrast. It explicitly states that this type of worldly service is limited by space and time and 'does not yield spiritual fruits,' unlike the service of writing the biographies of saints or, most importantly, one's own Sadguru. The mention is purely illustrative.