h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

With the advent of the Dark Ages around 500, the upheavals in society saw a decline in clerical discipline and with it, a return to marriage and even the keeping of concubines by priests. During this time, the wealth of the church was also increasing, a development not lost on Rome. Many priests were leaving church lands to their heirs, and others handed down land of their own through primogeniture. The Holy See saw that a return to the celibacy rule would result in a real-estate bonanza, and in about 1018 Pope Benedict VIII put teeth in the Elvira decree by forbidding descendents of priests to inherit property. Later, in the 11th century, Pope Gregory VII, who had assumed vast power by declaring himself the supreme authority over all souls, went even further by proscribing married priests from saying mass; he also forbid parishioners from attending masses said by them. Scholars believe that the first written law forbidding the clergy to marry was finally handed down at the Second Lateran Council in 1139.

He held a Council at Pavia in 1018 which legislated against the prevailing abuses of simony and clerical marriage