Zarin

One of the greatest mysteries in history has been why the Mongols never returned to finish off their conquest of Europe? Ostensibly, the most common reason given by history is that they withdrew from Europe, when Ogedei Khan died, to attend a required Khanate gathering.This was necessary to decide who the next Great Khan would be.
The newly selected Great Khan may have believed it was more important to consolidate what was a divided empire of four Khanates. Ones originally established out of his huge Empire by Genghis Khan and divided among his children.
My feeling is that the Mongols decided that there were other more "fattened" fish in the sea and decided to turn their attention towards the rich civilizations of the Middle East, finish off southern China, take the remainder of India, conquer Korea and invade Japan. Upon finishing this agenda they would then attack Constantinople and absorb the rich Byzantine Empire..traveling via this route back into and eventually taking the weak divided principalities of western Europe.
Europe, at this time was not a rich or even a prosperous area, so the Mongols may have given it a much lower priority for conquest. Fate being what it was, the Mongols were eventually forestalled in India and Egypt and the great invasion fleet headed for Japan was destroyed by a Typhoon. The momentum of Mongol conquest came to a halt.
The Chinese eventually threw off the yoke of the Mongols after Kulbai Khan died. However, the Mongols still retained vassal states and received tribute from Russia, Poland and other parts of Europe for at least a hundred years after they withdrew.Which tells how feared they were by these particular areas of Europe.

C0ldf1re

There are two reasons that I have heard:

1. The Mongols relied on horse archers, who relied on composite bows (short bows made with horn and animal glue.) Wooden bows, such as the later six-foot English longbow, were too clumsy to use on horseback! But composite bows fell apart in the damp conditions of western Europe.

2. After the death of Genghis, the Empire was divided and subjected to internal strife. Genghis's successors hated each other far more than they could ever hate strangers! So they fought each other, rather than the western Europeans.

pugsville

Because they knew they could not do it.

C0ldf1re

Begging your pardon, but after all their victories elsewhere, they probably thought that they could do it. If their Empire had stayed united, then, even with their difficulties using composite bows in the wet, they might well have done so.

Mr. Rhombus

Number 2 stands out in my mind as the main reason. The Mongols certainly, if they had stayed united, would have tried to return for an invasion on the rest of europe.

pugsville

It was a long long way away and the cost versus gain wasnt attractive or they would have been back. Naturally things closer to home were more important. The Mongol Invasion was in real terms an attempt to conquer europe, they might have thought so at the start, but their invasion really only strong enough against the weaker eastern states with wide plains.

They would have to back in real force, and they didnt have the resources to give it a real go.

DreamWeaver

Was there anything in Europe really worth having?

Europe is a considerable distance from the centre of the Mongol Empire, and in comparison to China, India and the Middle East, targets that are much closer and offer greater reward, what would be the point.

glory_man_utd

Not being pedantic, but after Chinggis Death the empire did not fall apart. It was in 1260, when Möngke Khan took over, the Mongol Empire became divided.

plutoboyz

They are not interested.

jungleplanewreck

I think it was a combination of the fact that Europe didn't have much to offer them at this time, and that their were huge divisions after the death of Genghis.