The historian Alan Gallay speculates that the Shawnee migrations of the middle to late 17th century were probably driven by the Beaver Wars, which began in the 1640s. Nations of the Iroquois Confederacy invaded from the east to secure the Ohio Valley for hunting grounds. The Shawnee became known for their widespread settlements, extending from Pennsylvania to Illinois and to Georgia. Among their known villages were "Eskippakithiki" in Kentucky, "Sonnionto" (also known as Lower Shawneetown) in Ohio, "Chalakagay" near what is now Sylacauga, Alabama, "Chalahgawtha" at the site of present-day Chillicothe, Ohio, Old Shawneetown, Illinois, and Suwanee, Georgia. Their language became a "lingua franca" for trade among numerous tribes. They became leaders among the tribes, initiating and sustaining pan-Indian resistance to European and Euro-American expansion.