The first half (or past) reminded me much of the Highlander mythos. Born to ordinary folk, these immortals leave or escape their pasts and survive. Mostly a collection of short tales. Then in the 20th century they start to seek each other out. After the meetup - no beheading or quickening here - they work together to give all of humanity immortality. Things get pretty weird after that, and they are exiled again - this time to the stars.

In this book, Poul Anderson has a chance to explore history and immortality, science and first contact - all with the same cast of characters. They are not the deepest characters, because the focus here is on the story. Much of their history was based on true events, and therefore enjoyable to me. The latter half of the book has similarities to [b:Tau Zero|240617|Tau Zero|Poul Anderson|https://images.gr-assets.com/books/1389216838s/240617.jpg|598009], written nearly 20 years earlier by the same author.

I read this as part of an 80s science fiction challenge. In an era of cyberpunks and fantasies, this book recalls an earlier era, with science instead of space opera. This resulted in a satisfying end to that decade.