"Transportation" as a legal sentence refers to the practice by the British government of transporting convicts to Australia and present day Tasmania (then known as Van Diemen's Land) from the late 1700s to the mid-1800s.
Many of the convicts sent "down under" were guilty of minor offenses or were political rebels. A number of Irish who resisted British rule were "sentenced to transportation" and would never see Ireland again.
It has been estimated that more than 150,000 convicts were transported from England, beginning in 1788.
A strong Anti-Transportation Movement began in Australia to protest the practice in the 1850s, and transportation as a punishment was finally ended in 1867.