I can't say I'm finished with this because this is a book I find myself constantly picking up to peruse, to fact-check a show I'm watching or book I'm reading, or to help me untangle the complicated, intertwined royal family so I can figure out where a particularly squicky nephew fits into the line of succession. I can flip to any point, start reading, and find myself completely engrossed in the intrigue, treachery, backstabbing, plotting, betrothals and marriages, dynastic takeovers and takedowns, and other assorted shenanigans that take place whenever a crown and an important plot of land is involved. Each short biography is packed with information, enough to give a general overview of the monarch while whetting the appetite to know more (helpfully guided by the extensive bibliography at the back). Additionally there are numerous genealogical charts (including several side charts detailing those royal children born on the wrong side of the blanket, their offspring as well as their descendants; it's amazing how many bastards circled back around and became the ancestors of legitimate kings and queens), helpful timelines, and a fascinating section at the front called "The Royal Book of Records" which is full of lists like The Most Gruesome or Unusual Deaths, The Shortest Royal Marriages, and The Monarchs with the Most Children.
While a little bit of author bias creeps in here and there, considering this book represents 2000 years of British regal history and covers nearly a thousand monarchs, it's quite an excusable slip considering you won't find this kind of exhaustive and invaluable reference material packed into any other single, relatively compact book. Honestly, I wish he done a similar reference tome for the royals of France as they're quite the tricky bunch to figure out! I've read and handled my copy so many times, it's nearly been worn to shreds. I'm going to have to buy another copy soon, maybe this time get a hardback edition so that it might stand up to the repetitive handling better.