To understand how you deploy an Azure Active Directory you need to understand that Azure Active Directory is directly connected to your Azure subscription. So, the Azure accountsubscription administration is always the first service administrator for your Azure environment. There can only be one account administrator per Azure subscription. The account administrator is the only one who can manage Azure AD and subscription connections. If you lose your administrator credentials or lose access to the administrator account, you can no longer manage your subscription.
You should therefore plan who will create your subscription and which account is the account administrator. To create a subscription, the subscription administrator must have a Microsoft Accounts or former named Live ID or Microsoft Account, Azure Active Directory account. This can be created, for example, via Office 365 before...