What was the central issue at the heart of the lay investiture controversy?

The lay investiture controversy primarily revolved around the struggle between secular rulers and the Church regarding who had the authority to appoint church officials, such as bishops and abbots. This conflict highlighted the broader tension between temporal (state) power and spiritual (church) authority. Secular leaders typically wanted to assert their influence over church appointments to ensure loyalty and align ecclesiastical power with their political interests.

In contrast, the Church aimed to maintain its autonomy and the integrity of church offices, believing that spiritual leaders should be appointed without interference from political entities. The resolution of this conflict was a significant factor in shaping the relationship between the Church and European monarchies, leading to events like the Concordat of Worms in 1122, which attempted to balance the competing interests by allowing the church to have a say in the appointment of bishops while still permitting some level of royal influence.

The other options touch on relevant themes in church-state relations but do not capture the central issue as effectively. Taxation of the clergy, while a matter of concern, was more of a financial disagreement, and the election of popes by nobility or the distribution of church lands pertain to specific aspects of church governance rather than the fundamental conflict over who holds authority to appoint