I can't answer your question for the Ottomans, unfortunately, as it's much later than I work (especially as the Ottomans didn't take control of the holy cities from the Mamluks until the early 16th century CE). I can, however, provide some details on the early period.

In the early Islamic period, leading the pilgrimage was a very important act which legitimized the ruler. Writing in the 9th century CE and reflecting on the second Islamic civil war in the 680s, the historian al-Ya'qubi importantly wrote "he who controls the two sanctuaries in Mecca and Medina and leads the pilgrimage thus merits the Caliphate." In the mind of Abbasid Muslims, you couldn't claim to be Caliph if you didn't control the holy cities and the hajj. So, you can see that it was an important legitimizing act in the early centuries.

With that said, however, the ruler himself didn't always have to actually be in attendance at the pilgrimage every year. The caliphs in the Umayyad and Abbasid periods would go every few years, and in the other years, they would send important family members or advisers in their place. It is very common in the early centuries to have the son(s) of the ruler lead the pilgrimage in his absence, which still served to demonstrate his authority and legitimacy.

While the nature of Arabic historiography makes it very difficult to answer some of the bigger questions of early Islamic history, when it comes to lists of governors and information like who led the pilgrimage in a particular year, we are remarkably well served.

I can't speak broadly, but one Islamic ruler of note who did make the Hajj was Musa I of Mali (more commonly known as Mansa Musa).

He made the Hajj in 1324, accompanied by, by some estimates, more than 70,000 men, including more than 10,000 slaves. The journey is notable for a number of reasons.

First, for quite a lot of the world it put West Africa on the map as a place of great wealth. And why was that? because Musa I brought an immense amount of gold with him. He brought so much gold that he tanked the gold market in Egypt and Arabia for a decade.

Second, was his devotion. Musa I's journey to Mecca and back took over a year and for that year he built a mosque every Friday. This may be somewhere between legend and fact, but still we can extrapolate that if this legend were created about Musa I, it likely would have been created out of his piety.

Finally, I want to go back to your original question, why do some leaders make the Hajj while others do not. One reason is certainly national security, as in, is rule secure enough, whether from external or internal threats to make the Hajj feasible? Another question is manpower, perhaps less so for the Ottomans, but for more distant Islamic nations, can you bring enough people to support a ruler traveling to Mecca? Third is the importance of piety. Musa I was notably pious compared to other leaders of Mali and later Songhai (this is not to say he was the most pious, but he was in the running). Piety was important for him personally, and as a display of power and obviously the Hajj, one of the pillars of Islam one of the greatest displays of piety possible. For other rulers and kingdoms it may have been that their religion was more nominal making the Hajj, a massive, expensive undertaking, not worth it.

I am not at my apartment so I'm not sure exactly what books and articles this info is from, but I will be home later if people would like sources.

And here's a fun fact about camels: Musa I would have traveled with a number of camels both for human transport and cargo. Later on, in the 16th and 17th centuries, there is evidence to suggest that camel caravans were as large as 10,000 camels! Which is an absurd amount of camels!

That source is: Ghislaine Lydon, On Trans-Saharan Trails: Islamic Law, Trade Networks, and Cross-Cultural Exchange in Nineteenth-Century West Africa

I really hope this thread gets lots of attention from our resident specialists. It's a fascinating part of history for me.

The Persians under Nadir Shah invaded and captured Bahrain when their ruler, Shaikh Jubayr, was away on Hajj in 1736. Was attacking while the ruler is on Hajj common ? Or was there an unwritten "chivalric" law that it's a dick move to attack a country whose ruler is away on the sacred pilgrimage.

Why didn't everyone in the muslim world declare war on the Qarmatian republic when they basically stopped the Hajj for a while, when they sacked Mecca in 930, stole and shattered the Black Stone ? How did the muslim world react when they found out Mecca could not be reached anymore because all pilgrims were slaughtered en masse ?

Sorry for threadjacking, CheekyGeth, but i do hope my questions will also help us understand how the Hajj was seen by the Muslim rulers.

During the golden age of the Ottoman Empire, the rulers were busy with wars, therefore they could not just leave everything and visit Mecca for an extended Period. Winter time was spent with planning the next expedition and from April to November was the expedition time.

Let's take Suleyman the Magnificent as an example. During his reign he was constantly warring with the Hungarians and the Persians. Imagine the constant need to plan, fight and governing. The ruler himself (during the height of the Ottoman Empire) was first hand responsible for these tasks because it was very important for a ruler to be involved personally in the matters of the state. They simply did not put going to Hajj as a priority because governing was the priority for these rulers. When you look in the history of the Ottoman Empire, it started to decline when the rulers decided that they would rather have more free time than be involved in the matters of the state.

There is also a relation between fighting the non Muslims and piety as well. Not only rulers but also "normal" Muslims from the Ottoman Empire saw fighting the "infidels" as a kind of a religious practice. For example, the famous adventurer Evliya Celebi (much later than the reign of Suleyman I) describes his willingness to go to the Balkans and to join the wars against the Hungarians/Austrians and he portrays this will as a religious practice.

Religion was an important factor for the Ottoman Rulers but governing and keeping the borders safe by means of war against the so called "infidels" was more important and such wars were seen as a religious duty.

Another interesting time period regarding Hajj and rulers was when the Hijaz was under the rule of ibn Zubayr—I'm at work so I can't check books, but I most recently read about this in "Jerusalem Beseiged". As the Umayyads ruled from Damascus, and the two holy cities were controlled by ibn Zubayr's caliphate, they took hold of a hadith (by whom I can't recall) which reasoned that to pray in Mecca was to pray, say, 10000x anywhere else, and in Medina 1000x anywhere else, and in Jerusalem 100x anywhere else (or some such mathematical structure).

They point being: the Umayyads advocated a less Hajj to Jerusalem over Mecca, so as to funnel the money (and social good will and support) that accompanies the event back into the Umayyad caliphate, and not into ibn Zubayr's.

This would have been during the reign of...Muawiyah...no no Yazid 1 and Abd al Malik (who finally defeated ibn Zubayr).

You are right in that Ottoman rulers never made the Hajj pilgrimage, but other rulers did. Perhaps the most famous Muslim ruler to make the Hajj was Mansa Musa of the Mali Empire. In 1342, Mansa Musa, whose empire was built upon conquest, salt, and slaves, took tens of thousands of people with him on the pilgrimage either as pilgrims or as servants. He also brought two tons of gold with him to give away as alms to the poor. To put this in perspective, he gave away so much cash to the poor in Cairo that he devalued the metal for 20 years.

Of course, part of the reason the Mali Empire collapsed a mere generation or so later might be because Mansa Musa gave away so much money and was so extravagant during the Hajj; sure, the Mali had other problems, including rebellious provinces, but the money could have been useful also.