Ottomans are very instrumental to the expansion of Saudi Arabia. Their era came after that of Selim in 1517. Selim too was so great and warlike during his time; he was able to capture several cities including Mecca and Medina in 1571. Ottomans on their part did not rest on their oars and they furthered the expansion of the present day Saudi Arabia, with all its promotional sporting goods. In the 16th century, they were able to add cities like Asir and Hejaz to the country and this further expanded the reach of Saudi Arabia. They were also able to capture Al Hasa region, which is on the Persian golf and this region had become part of the present day Saudi Arabia.
The ottomans regime was founded in 1299 and it had become fully established by 1402. Its power rose between 1413 and 1453. Between 1453 and 1579, the regime was able to win lots of battles and more regions were added to the present day Saudi Arabia. During this period, the regime experienced an accelerated and progressive growth. Everything that has a beginning tends to always have an end. The regime started diminishing in power between 1579 and 1683.
Capturing of the Al Hasa region proved to be a great achievement; since the region had proved to be the most populated part of the present day Saudi Arabia. The ottoman regime was one soaked in war and conflict. Most of the conflicts were actually external. There was always war to be fought and there were always new areas to be captured.
At the start of the ottomans regime, Saudi Arabia was a very strong country. Many other kings and rulers round about the country feared and respected Saudi Arabia. But as the regime came to the tail ends of its reign, things tend to turn the other way. The regime was very able to control all its regions at the start of things, but this control waned towards the tail end.
The regime actually stood tall and strong for several centuries; it weakened due to problem with the central authority. There was a decentralized government system that gave some of the regions like Mecca, Sharrifs and Hejaz the control over their territories. The central authority would send a governor to oversee the affairs of places like these. A garrison would also be posted in the regions to maintain the peace and establish the presence of the regime.
In the 17th century however, there was a battle for the sole of the Al Hasa region between the ottomans regime and the Arabs. The Arabs ended up winning the battle and took control of this region. Later in the 19th century, the ottomans regime put their acts together and retook the region from the Arabs.
Conclusion
While the ottomans regime was able to wield its power over many of the regions that make up Saudi Arabia today, it was not really able to penetrate into the interior parts. It is true that the ottomans regime laid claim to the interior, but the claim was just a nominal suzerainty.