  Meteors can be classified into either sporadic meteors or showery meteors. We
compile the meteor records in the astronomical archives in the Chronicle of the
Koryo dynasty (918-1392), and investigate the spatial distribution of meteor
streams along the orbit of the Earth from the 10th century to the 14th century.
We see that meteors from meteor streams signalize themselves over noisy
sporadic meteors, and that the seasonal activity of sporadic meteors was
apparently regular. We discover the presence of a few meteor streams by
analysing about 700 meteors in the Koryo period. We also compile the records of
meteor showers and storms in the chronicles of Korea, Japan, China, Arab, and
Europe, and compare their appearance dates with those of showers obtained
above, as well as with the modern observations. We confirm that the three sets
of data are in agreement with each other. The representative meteor showers are
the Perseids, the Leonids, and the $\eta$-Aquarids/Orionids pair formed by
Halley's comet. The other weak or relic meteor streams are also observable but
uncertain. Hence, we witness the regularity of meteor activity, which is seen
to persist for a millennium.
