This should explain why Sylhetis are a bit more religious, How islam came to Bangladesh, and Where exactly did it start in Bangladesh

all praise due to allah swt for landing hazrat shah jalal in bangladesh.

http://www.islam-bd.org/heros/shahjalal/shahjalal.html

Shah Jalal is one of the most revered legendary Islamic heroes of Bangladesh and one of the key founding fathers of Islam in the country. He was a great saint and a great warrior. He, along with his disciples, had unique contribution in liberating the people of Sylhet region both from the racial rule of the Hindu kings and the prejudices of paganism.

His full full name is Sheikh-ul Mashaek Mokhdum Sheikh Shah Jalal Mozorrodh Bin Muhammed. Although historians are divided on the issue of his birth-palce, the majority of them thinks that he was born in 1271 in Konya, Turky.

Shah Jalal's father was contemporary to Mawlana Jalal Uddin Rumi. Rumi's mazaar is also situated in Shah Jalal's birthplace, Konya in Turky. His ancestors came from Yemen, hence he is also called the Mozorrodh-e-Yemeni. Shah Jalal was raised by his maternal uncle, Syed Ahemd Kabir, in Mecca. He became a Hafiz (those who know the Holy Koran by heart) and also became proficient in Islamic theology. Legend has it that one day his uncle gave him a handful of earth and ask him to go to Hindustan with the instruction that whichever place in Hindustan matches this earth completely in smell and color, he should settle down for preaching and establishing Islam.

Shah Jalal journeyed eastward and reached Hindustan (modern India) in c. 1300. In Ajmir, he met the great Sufi mystic (Dervish/Pir), Kwaja Gharibnawaz Moinuddin Hasan Chisty. He also met with Nizam Uddin Awlia (1236-1325), a prominent Dervish, in Delhi. Nizam Uddin requested him to go to Sylhet to rescue Sheikh Burhan Uddin. The Sheikh was only a handful of Muslims living in the kingdom of a Hindu King, Gaur Gavindha. He secretly slaughtered a cow to perform his son's Akika (christening of child in Muslim culture). It is said that a crow carried a piece of meat and dropped it in the king's yard. The enraged king ordered killing of the Sheikh's son and the Sheikh himself was imprisoned. Sheikh Burhan Uddin's mazaar (shrine) is located in the banks of river Surma in Sylhet town.

Shah Jalal reached Sylhet with 360 Awlias (disciples). Some of the awlias originally followed him from Delhi, and some joined on the way to Sylhet. Knowing that Shah Jalal was advancing toward Sylhet, the king removed all ferry boats from the river Surma. Legend has it that Shah Jalal crossed the river Surma by sitting in a Zainamaaz (prayer rug). Muslim force was defeated by the king twice previously. However, this time the king ran away after being deafeated by the force led by Shah Jalal after a fierce battle. Shah Jalal also found a match of the earth his uncle once gave him. He settled down in a placed called Drag Mahallah, near Choukidhiki. He preached Islam from there. He and his disciples also travelled as far as Mymensingh and Dhaka.

In his book "Afdalul Hawaade", poet Hazrat Amir Khosru gave exact dates of Shah Jalal's travel to Sylhet. Khosru was a Moghul court poet, and considered the founder of Urdu language. Persian traveller, Ibn Batuta, also came to Sylhet to meet Shah Jalal.

The exact date of his death is unknown. According to Ibn Batuta, it was 1347. He died at Sylhet, Bangladesh.

Shah Jalal's nephew, Hazrat Shah Paran, lived out of town, in Major Tila area. Legend says that he was of very high temper and would curse people when they are unruly and the curse would come true. To save people from his wrath, Shah Jalal ordered him to settle down just the outskirt of the town.