The first half - Thucydides. The second half Xenophon.
My expert teacher, of ancient history, taught me that Thucydidies was a well known greek historian, who faught in the pelopennesian wars, and wrote the main account of what we know on the pelopennesian wars.
The Spartan alliance
It is war, not was. It is the Pelopennesian War.
Lma00 431 bc
Sun Tsu wrote it, around 500BC. This is Chinese History, by the way, not European History
plague was the main even that kept Athens from conquering Sparta
Thucydides and Xenephon.
'The History of the Peloponnesian War'
Thucydides wrote on the first half of the War. The second and final stage was covered by Xenophon.
Herodotus of Halicarnassus.
The Naval History of the War of 1812 was written by Theodore Roosevelt. He wrote this classic, as its still regarded today, just as he was graduating from Harvard.
Thucydides History of the Peloponnesian War.