"The Sarmatians 600 BC - AD 450" by Richard Brzezinski and Mariusz Mielczarek is an excellent resource about Sarmatians. The book lives up to the typical Osprey "Men-at-Arms" series standards; it provides a brief overview, along with many photographs of paintings and sculptures, and contains color plates depicting various scenes. The book is great as it draws from many accounts of ancient texts that mention the Sarmatians.
The Sarmatians were a nomadic people that came out of Iran in ancient times. There were various groups of Sarmatians, such as the Alans, Iazyges, Roxolani, Siraces, and Aorsi. My interest in the Sarmatians stems from the 17th century Polish nobles belief that they were descended from the Sarmatians. They even made their armor look like what they thought Sarmatian armor was like. This book provided me with insight into this subject. This book brushes on this topic, but by no means focuses on it and is only a small fragment of the information contained within this book.
The authors state that for centuries it was believed that the Sarmatians were the ancestors of the Slavs, as they lived on the same land and as one appeared the other disappeared. Furthermore, the authors state:
"Linguists and archeologists have long dismissed this idea; but at the same time have turned up evidence of the seminal influence of the Sarmatians on Slav language, art and religion. Indeed, it is now accepted that the Sarmatians merged in with pre-Slavic populations. Both Serb and Croat seem to be Slavicised Alan tribal names. The myth of Sarmatian origins took a strong hold in Poland, where the Alans had a minor presence. (p.39)"
Dismissing this idea into the class of myth may be just a form of extreme skepticism. It seems contradictory that the idea is dismissed, yet evidence in support of it has grown. Perhaps, it just goes to show the ancient beliefs were accurate in some cases, and modern re-thinking only distorts us from the truth.
Personally, I found it interesting that swords with ring shaped pommels were popular among the Sarmatians from the 2nd century BC to the 2nd century AD, as my family coat of arms has a sword with a ring shaped pommel.