portmanteau

a case of a bag for carrying clothing or other belongings when traveling; (originally) one of a form suitable for carrying on horseback; (now esp.) one in the form of a stiff leather case hinged at the back to open into two equal parts.

//He was riding the roan horse, in the frock coat and the beaver hat which they knew and with his legs wrapped in a piece of tarpaulin; he had a portmanteau on his pommel and he was carrying a small woven basket on his arm// (AA 34).