The Siddhantasiromani was composed in 1150 CE by the celebrated mathematician-astronomer Bhaskaracarya. All the 460 verses of the 12 chapters of the Grahaganitadhyaya part of it have been translated afresh in this work. What is more, the Vasanabhasya has been translated into English for the first time. Explanatory notes based on the vasana of Bhaskara have been provided in modern notation, with a large number of diagrams to facilitate understanding. The present work is divided into two volumes. The first volume is devoted to the three chapters, the Madhyamadhikara, Spastadhikara and the Triprasnadhikara. The second volume has the rest of the nine chapters, including the ones on the eclipses, conjunctions of planets and stars, etc. The first volume also has a comprehensive introduction, and two explanatory appendices, which make this book reasonably self-contained. The present book is indeed a pioneering and monumental effort to translate the entire Vasanabhasya for the 460 verses of the Grahaganitadhyaya. Its technical content is explained so that the students and scholars have a clear access to this wonderful exposition of Indian astronomy including its methodology by Bhaskara.