Which is the most important Institutions of a Islamic State?

The most important institution introduced was an Advisory Council or Majlis-e-Shoora to meet the Quranic injunctions of acting after consultation.

Although the members of the Shoora were chosen by the Khalifa from amongst both the Muhajirs and Ansars, the constitution of the Shoora did not change with the Khalifa as the selection was based on no other consideration than the merit.

This made the Shoora a very important body, more or less, of permanent nature. It was in no way subordinates or subservient to the Khalifa. It appears that proceedings for the impeachment of the Khalifa could also be taken by the Shore?

All matters of administration had to be placed before the Shoora which decided by a majority of votes after full discussion.

The voting was not on any party basis but each member tried to convine the other by the sheer force of his arguments supported by Quranic injunctions and Hadith.

The endeavour was always to attain unanimity which was more often than not obtained because, all acted with a sense of collective responsibility and with an open mind free from any bias or prejudice.

The Shoora in effect was also the legislature of Islam. However, no law could be framed which was opposed to the Quran and Sunnah.

In fact, no law making was possible unless approved by the Shoora. In reaching a decision, the Shoora followed the democratic method of majority vote.