French navigator Jean Francois de Galaup, Comte de la Perouse (1741-88) distinguished himself in the naval war against Britain (1778—83) before leading the 18th century's best-equipped expedition to the Pacific (1785-88).
After visiting America's northwest coast, he explored Asia's north-eastern coasts and sailed through the strait between Sakhalin and Hokkaidō. Orders received in Kamchatka directing him towards New South Wales saw him arrive at Botany Bay shortly after Arthur Philip's First Fleet.
His two ships disappeared without a trace after sailing from there on March 10 1788. The wreckage was found off the coast of Vanikoro in the Solomon Islands nearly forty years later.
See here for a more detailed biographical sketch.