Eugene (Micky) Ryan was born in Ireland and studied medicine at Cork and Edinburgh. After a period of private practice in London he was commissioned into the RAMC in 1901 and saw active service in South Africa. After meeting Douglas Haig in 1912 the two men's lives became intertwined and their relationship, while primarily professional, blossomed into a friendship of mutual respect. Ryan became Medical Officer to HQ 1 Corps under Haig in August 1914 and, when Haig took command of 1st Army in December 1914, Ryan moved with him. Ryan also saw service commanding two Casualty Clearing Centres before being appointed Medical Officer to the C in C (Haig) in September 1916 and remained in this key post until April 1919. Ryan was in effect the Haig family doctor delivering Lady Haig's long awaited son and heir in March 1918. The correspondence in this book proves the degree of trust and friendship between Ryan and both Haig and his wife. These diaries would be a find record of service but their constant reference to Haig and his family make them of considerable historical significance and will be eagerly read by all those with an interest Haig and The Great War.