One of these is not an organ of the Commonwealth of Nations

The **Commonwealth of Nations**, often simply known as the **Commonwealth**, is a political association of 56 member states, most of which are former territories of the British Empire. It is indeed essential to recognize its main organs.

The **Commonwealth Secretariat** is a principal **organ**. It is responsible for the administrative work of the Commonwealth, serving member governments, and acting as a central agency of cooperation for policy development and consensus-building among countries.

The **Assembly of Heads of State and Government** does not exist within the Commonwealth framework as an independent organ. Instead, these leaders meet at the Commonwealth Heads of Government Meeting (CHOGM), which is a summit for current government leaders to discuss pertinent global and Commonwealth issues.

The **Conference of Prime Ministers** is not a permanent organ of the Commonwealth, but it refers historically to meetings of the heads of government, which is similar to CHOGM today.

The **Fund for Technical Cooperation** is an integral financial resource managed by the Commonwealth Secretariat, not an organ in itself. It supports member countries in achieving economic development through technical assistance.

In conclusion, the **Assembly of Heads of State and Government**, as stated, is not an independent **organ** of the Commonwealth of Nations.