Generally, there are four basic principles in international penal law, which help the legislators to declare penal competency. Each principle has its own reasons and circumstances.
In fact, we are dealing with four principles: 1-The principle of territorial competency of penal competency, 2-The principle of personal jurisdiction of penal competency, 3- The principle of real competency of penal competency, 4- The principle of universe jurisdiction (international),
Since the principle of territorial competency in international penal law is the subject of the first and main part, and this thesis is a comparative study of competency (territorial) in the penal law of Iran and Lebanon. For the same reason, contents of this thesis are divided into several parts; each part discusses different aspects of this principle including definition, concept, history, results, and exceptions from the point of view of both countries (Iran and Lebanon).
Territorial competency consists of penal competency over crimes committed in the territory of that country, in other words, it means that the crimes committed in the territory of a country are decided according to the rules of the same country.
The territorial competency has two aspects: one is positive and the other is negative. The positive aspect is that, all people who commit crimes within the territorial sovereignty of crimes are tried according to the law of Iran, except in the exceptional cases, and the negative aspect is that all people who commit the crimes outside the territorial sovereignty of crimes cannot be tried in Iran, except in the exceptional cases.
In this thesis, the territory of sovereignty (i.e.; 1- land borders, 2-water borders: ships, 3- aerial borders) have been studied and compared in both countries of Iran and Lebanon. The existing similarity and differences will be also discussed.
In continuation, it should be noted that the exceptions to the principle of territorial competency such as political and parliamentary immunity which are practically limited to representation tasks have been discussed.
According to what was said, this thesis attempts to give definitions for concept of competency, and investigation approach for detecting the crime scene, it also discusses side issues such as immediate and ongoing crimes, simple and compounds crimes, absolute and constrained crimes, starting and assistance in crimes, and the last but not the least is to study the investigation approach and to discuss the differences between the penal policy in Iran and Lebanon with respect to the above mentioned issues.
Keywords: territorial competency, personal jurisdiction, international jurisdiction (international).