The term "Crusades" refers to a series of religious wars fought between the 11th and 15th centuries. The most well-known and documented Crusades occurred in the Eastern Mediterranean region, where Christians from Western Europe sought to reclaim Jerusalem and other holy sites from Muslim control. However, there were also crusades within Europe, known as the Northern Crusades or Baltic Crusades, which aimed to convert or conquer pagan and non-Christian regions in the north.

1. **Eastern Crusades:**
- **First Crusade (1096-1099):** Initiated by Pope Urban II, the First Crusade aimed to recapture Jerusalem from Muslim control. The crusaders succeeded in capturing Jerusalem in 1099, establishing several Crusader states in the region.

- **Subsequent Crusades:** Several other Crusades followed over the next centuries, including the Second Crusade (1147-1149), the Third Crusade (1189-1192), and others. Each had varying degrees of success and failure, and their impact on the balance of power in the region was complex.

2. **Northern Crusades (Baltic Crusades):**
- These crusades were directed against the pagan peoples of Northern Europe, particularly in the Baltic region. The goal was to convert these non-Christians to Christianity and to expand Christian territories.

- **Livonian Crusade (1198-1290):** Focused on the territories around the Gulf of Riga and the Livonian Brothers of the Sword, a military order, played a significant role.

- **Teutonic Knights:** The Teutonic Order, a Germanic military order, played a crucial role in the Northern Crusades. They were involved in the Prussian Crusade (1208-1226) and later the Lithuanian Crusade (1326-1386).

3. **Albigensian Crusade (1209-1229):**
- This crusade took place in Southern France against the Cathars, a Christian sect considered heretical by the Catholic Church. The Albigensian Crusade resulted in the suppression of the Cathars and solidified Catholic Church authority in the region.

While the Crusades had religious motivations, they were also influenced by political, economic, and social factors. They had profound and lasting effects on the cultures and societies involved, shaping the course of European and Middle Eastern history. Additionally, the Crusades left a legacy of tension and animosity between different religious and cultural groups that persists to some extent in the present day.