The Ottoman Empire was founded by Osman 1 (the first).
For entertainment and religious reasons
The order helped by acquiring wealth to ransom Christians who were taken by Non-Christians during the crusades. Many crusaders were captured and countries had to pay huge amounts of money for them which was often not worth it. The trinity was established to help the crusaders by getting those people home.
They migrate due to altitudes during different times of the season
An open question is a question that has not had a final answer. Hope I helped.
