Complex sentence: Along with the "Pontificale", Ealdred may have brought back from Cologne the first manuscript of the "Cambridge Songs" to enter England, a collection of Latin Goliardic songs which became famous in the Middle Ages.
Split into simpler sentences: Along with the "Pontificale", Ealdred may have brought back from Cologne the first manuscript of the "Cambridge Songs" to enter England. This work was a collection of Latin Goliardic songs, and became famous in the Middle Ages.