The central idea of this book is brilliant: a survey of the world in the year 1,000 A.D. This approach differs from most history books, which sacrifice global context in favor of particular details. By taking a wider view, The Year 1000 gives readers a birds-eye perspective on technological, economic, and political trends across the globe at the turn of the last millenium.
One example of innovation at this time was increasingly accurate calendars. Establishing correct lengths for days, months, and years all depended on empirical observation. Knowing when to plant, when to harvest, and when to pay your taxes were all important concerns (p. 148-9). In this respect, Eurasian empires had similar needs those served by Mayan calendars as discussed in The Fifth Sun.
However, in its eagerness to describe connections between disparate empires, the book sometimes goes beyond the facts supported by the best available evidence. For example, in trying to link Viking voyages to Newfoundland with the Mayan Empire of Central America, the author explores claims that apparently light-haired individuals depicted in Mayan murals were Viking captives. Despite these minor flaws, the book is worthwhile for the wide perspective that it offers.