The Tataru's Grand Endeavor questline first started in Final Fantasy patch 6.1, but with Patch 6.15 has arrived, it's finally available. So how do you unlock and start the Tataru's Grand Endeavor quests in Final Fantasy XIV?

How to Unlock the Tataru's Grand Endeavor quest?

1). You need only to have a Disciple of War or Magic job at level 90 and have completed the Endwalker main story.

2). You will also need to complete the Patch 6.1 "Newfound Adventure" main questline to unlock Tataru's Grand Endeavor. If you're coming back from Endwalker's initial launch, Newfound Adventure can be started by none other than Tataru herself at X:6.0 Y:5.9 at the Rising Stones in Mor Dhona.

3). Following this main story quest eventually leads to the current ending quest, A Satrap's Duty.

4). Completing this step will unlock the ability to see the Tataru's Grand Endeavor quest in Old Sharlayan.

How to Start the Tataru's Grand Endeavor quest?

Once the above prerequisites are complete, you can go to Old Sharlayan and speak to Tataru's new assistant, Mehdjina (x: 11.8, y:9.8).

She will have two quests in succession: Small Business, Big Dreams, and Soaring Profits.

1). Small Business, Big Dreams

The starting quest for Tataru's Grand Endeavor is called "Small Business, Big Dreams." It's a level 90 quest found in Old Sharlayan near The Agora, which is just a short walk from the central Aetheryte Plaza.

You'll discover that Tataru wants to expand the influence of her business to develop trade relations around the world. She convinces you to act as her sales pitch person and sends you off to the three main Eorzean city states to meet with clients.

First, go to Limsa Lominsa Lower Decks and speak to Hasthwab (x:5, y:15), who will summon Sicard.

After getting his confirmation, go to New Gridania and talk to Mother Miounne (x:11.7, y:13.5). She doesn't know A-Ruhn-Senna's exact location but thinks he is out on a mission. Attempt to leave through the main gates, and the Padjal will arrive and agree to help.

Next, go to Ul'dah and speak to the Usher (x:10.7, y:11.2), and a cutscene with Pipin will play out, much like the others.

Once all three have confirmed, go back to Mehdjina to finish the quest.

2). Soaring Profits

For the second quest, Mehdjina will suggest going to Emmanellin. To do so, you must complete the entire Shadow of Mhach 24-man raid series at any point in the past. You also must turn in the final raid-related story quest, A Redbill Farewell.

After doing so, one can speak to Laniaitte at The Sea of Clouds (x: 17, y:37.3).

This will reintroduce Leofard from the previous raids. He will give you a basic merchant disguise buff - if lost, speak to Stacia in Idyllshire at any point to reapply it.

You will have 30 minutes to three marked residences around Idyllshire.

Next, escort Leofard to the highlighted location to play out a cutscene.

At its end, it will introduce the painter Duremert, who will now offer his services to paint various portraits for 20,000 FFXIV Gil each.

Finally, you can purchase housing items depicting some of the major Final Fantasy XIV protagonists, including Y'shtola, Thancred, and Urianger.

Rewards for Tataru's Grand Endeavor quests

While this Final Fantasy XIV questline doesn't currently have a significant reward, it will probably lead to one in patch 6.5. This will likely be a cosmetic item, minion, or other non-combat-related goods. 

That's all you need to know about how to unlock & start Tataru's Grand Endeavor. Be sure to search for ffxiv4gil.com for more tips and information on the game.