Ahmadiyya is a sect which was founded by a man called Mirza Ghulam Ahmed, who was from Qadian, a village in Punjab(India) at the end of the 19th century. He believed himself to be Mahdi, Messiah and Jesus(AS) in one person, he gained quite a lot of followers but his claims were rejected by the orthodox Ulema as the ad-dajjal(anti-Christ) hadn't appeared and Mirza himself didn't share any of the characteristics of the Mahdi. They also do not believe that Jesus(AS) was raised to Allah(SWT) but instead say he left for India and his grave was to be found in Kashmir. They furthermore reject Jihad with the use of sword, saying nowadays there was no need for it anymore they are known for their pacifistic beliefs their motto is "Love for all, Hatred for none".
A lot of them migrated to Pakistan after partition where they faced a lot of discrimination, they were proclaimed non-Muslims by the Ulema in the 20th century, thus not eligible to go on pilgrimage to Mecca. Under Zia al-Haq's rule many of them sought refuge in Germany and they have a lot of mosques and centers here. Their annual meeting(Jalsa Salana) is known and a lot of non-Muslims visit it as well.
They also have their own definition of Khilafat and currently their 5th Khalifa is "in rule", but he is more of a spiritual leader to them. Each member has to pay a certain amount of his income to the Jamaat, this payment is called Chanda. Women have their own organisation within the Jamaa called Lajna Imaillah, they organise events seperated and independent from the main body. They're also very strict when it comes to Hijab in most cases. People can be expelled from the Jamaat if they break certain rules, e.g. are caught having sex priour to marriage.
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