This book is an expanded version of the notes of a course of lectures given by at the Tata Institute of Fundamental Research in 1998. It deals with several important results and methods in transcendental number theory. First, the classical result of LindemannWeierstrass and its applications are dealt with. Subsequently, Siegel's theory of \(E\)functions is developed systematically, culminating in Shidlovskii's theorem on the algebraic independence of the values of the \(E\)functions satisfying a system of differential equations at certain algebraic values. Proof of the GelfondSchneider Theorem is given based on the method of interpolation determinants introduced in 1992 by M. Laurent. The author's famous result in 1996 on the algebraic independence of the values of the Ramanujan functions is the main theme of the reminder of the book. After deriving several beautiful consequences of his result, the author develops the algebraic material necessary for the proof. The two important technical tools in the proof are Philippon's criterion for algebraic independence and zero bound for Ramanujan functions. The proofs of these are covered in detail. The author also presents a direct method, without using any criterion for algebraic independence as that of Philippon, by which one can obtain lower bounds for transcendence degree of finitely generated field \(\mathbb Q(\omega_1,\ldots,\omega_m)\). This is a contribution towards Schanuel's conjecture. The book is selfcontained and the proofs are clear and lucid. A brief history of the topics is also given. Some sections intersect with Chapters 3 and 10 of Introduction to Algebraic Independence Theory, Lecture Notes in Mathematics, Springer, 1752, edited by Yu. V. Nesterenko and P. Philippon. Narosa Publishing House for the Tata Institute of Fundamental Research. Distributed worldwide except in India, Bangladesh, Bhutan, Maldavis, Nepal, Pakistan, and Sri Lanka. Readership Graduate students and research mathematicians interested in number theory. Table of Contents  LindemannWeierstrass theorem
 \(E\)functions and Shidlovskii's theorem
 Small transcendence degree (exponential function)
 Small transcendence degree (modular functions)
 Algebraic fundamentals
 Philippon's criterion of algebraic independence
 Fields of large transcendence degree
 Multiplicity estimates
