user15: I know that in the early days of Buddhism, it was for men only. To practice, you had to be a monk, and to be a monk, you had to be a man. Perhaps this reflects the attitudes of the time, but today, my experience of Buddhism has been as something that welcomes men and women equally, even when that's still in a segregated way.
Historically, when did this change come about, and what first triggered it?

user-1: The sutta story of the ordination of the Buddha's aunt, Pajapati, at the behest of Ananda, implies that the order of nuns did not exist, is dubious, since there is another story in the Vinaya in which Pajpati clearly joins an existing order of nuns. If one takes a comprehensive view, the two stories are irreconcilable, whereas it is inconceivable that the Vinaya story would be invented in response to the sutta story. 
Therefore, the sutta story must be a fabrication by monks to justify their discriminatory attitude to the order of nuns, mirroring the deep misogyny of late Vedic society. The establishment of the order of nuns appears to have been allowed as a concession in the First Buddhist Council, headed by Mahakassapa, an ascetic, despite the Buddha's more lax attitude to women, for which Ananda was blamed. 
Pajapati sought ordination when the Buddha's father, Suddhodana, died, four years after the Buddha's Enlightenment experience. Possibly the Buddha was concerned about the safety or reputation of the nuns and delayed ordaining women somewhat, but the suttas clearly show the Buddha interacting with and teaching women without making any difference between men and women. He also emphasizes the importance of there being women at all stages of spiritual attainment in order for the sangha to be complete.

user413: Re: James Jenkins question, "Is there a date to go with this occurrence?" - the answer depends upon when we date key events in the Buddha's lifetime. There is some scholarly debate about this question.  
According to the "Bhadda Kapilani Theri Apadana", one of the chapters of the Theri Apadana book of the canonical Pali-text Khuddaka Nikaya collection, the Buddhist Bhikkhuni Sangha was established and it became possible for women to enter the Buddhist monastic community five years after the establishment of the Bhikkhu Sangha.
According to Sri Lankan Theravada Buddhist tradition, this event is commemorated on the lunar calendar on the full moon of September.
According to the reckoning of the Thai Buddhist Era, the full moon of September 2014 CE will be the 2597th anniversary of the foundation of the Buddhist Bhikkhuni Sangha.
It is important to note that some monastic scholars, i.e., Bhikkhu Sujato, speculate that there may have been bhikkhunis, such as Bhadda Kundalakesi, prior to that date.  

user18: According to the texts (Cv 10), after the Buddha returned to visit his father in Kapilavatthu, his aunt and step-mother, Mahapajapati Gotami, followed him back to Vesali and eventually ordained her using the eight garu dhammas as her higher ordination. He then gave the injunction that the male monks were to ordain the female monks, which was the beginning of the bhikkhuni sangha.

1. Now Mahā-pajāpatī the Gotamī went up to the place where the Blessed One was, and bowed down before him, and stood respectfully on one side. And, so standing, Mahā-pajāpatī the Gotamī spake thus to the Blessed One: 'What course, Lord, should I pursue towards these women of the Sākya clan?'
Then the Blessed One taught Mahā-pajāpatī the Gotamī and incited her, and aroused her, and gladdened her with religious discourse; and she, so taught, incited, aroused, and gladdened, bowed down before the Blessed One, and keeping him on net right hand as she passed him, she departed thence.
Then the Blessed One, in that connexion, delivered a religious discourse, and said to the Bhikkhus, 'I allow Bhikkhunīs, O Bhikkhus, to receive the upasampadā initiation from Bhikkhus.'
2. Now those Bhikkhunīs said to Mahā-pajāpatī the Gotamī: 'Neither have you received the upasampadā initiation, nor have we; for it has thus been laid down by the Blessed One: "Bhikkhunīs are to be initiated by Bhikkhus."'
Then Mahā-pajāpatī the Gotamī went to the venerable Ānanda, and [repeated their words to him]. And the venerable Ānanda went to the Blessed One, and [repeated them to him].
'In that moment, Ānanda, when Mahā-pajāpatī the Gotamī took upon herself the Eight Chief Rules, that was to her as the upasampadā initiation.'
-- Cv 10.2 (Rhys-Davids, trans)


15: <p>I know that in the early days of Buddhism, it was for men only. To practice, you had to be a monk, and to be a monk, you had to be a man. Perhaps this reflects the attitudes of the time, but today, my experience of Buddhism has been as something that welcomes men and women equally, even when that's still in a segregated way.</p>

<p>Historically, when did this change come about, and what first triggered it?</p>
 -1: <p>The sutta story of the ordination of the Buddha's aunt, Pajapati, at the behest of Ananda, implies that the order of nuns did not exist, is dubious, since there is another story in the Vinaya in which Pajpati clearly joins an existing order of nuns. If one takes a comprehensive view, the two stories are irreconcilable, whereas it is inconceivable that the Vinaya story would be invented in response to the sutta story. </p>

<p>Therefore, the sutta story must be a fabrication by monks to justify their discriminatory attitude to the order of nuns, mirroring the deep misogyny of late Vedic society. The establishment of the order of nuns appears to have been allowed as a concession in the First Buddhist Council, headed by Mahakassapa, an ascetic, despite the Buddha's more lax attitude to women, for which Ananda was blamed. </p>

<p>Pajapati sought ordination when the Buddha's father, Suddhodana, died, four years after the Buddha's Enlightenment experience. Possibly the Buddha was concerned about the safety or reputation of the nuns and delayed ordaining women somewhat, but the suttas clearly show the Buddha interacting with and teaching women without making any difference between men and women. He also emphasizes the importance of there being women at all stages of spiritual attainment in order for the sangha to be complete.</p>
 413: <p>Re: James Jenkins question, "Is there a date to go with this occurrence?" - the answer depends upon when we date key events in the Buddha's lifetime. There is some scholarly debate about this question.  </p>

<p>According to the "Bhadda Kapilani Theri Apadana", one of the chapters of the Theri Apadana book of the canonical Pali-text Khuddaka Nikaya collection, the Buddhist Bhikkhuni Sangha was established and it became possible for women to enter the Buddhist monastic community five years after the establishment of the Bhikkhu Sangha.</p>

<p>According to Sri Lankan Theravada Buddhist tradition, this event is commemorated on the lunar calendar on the full moon of September.</p>

<p>According to the reckoning of the Thai Buddhist Era, the full moon of September 2014 CE will be the 2597th anniversary of the foundation of the Buddhist Bhikkhuni Sangha.</p>

<p>It is important to note that some monastic scholars, i.e., Bhikkhu Sujato, speculate that there may have been bhikkhunis, such as Bhadda Kundalakesi, prior to that date.  </p>
 18: <p>According to the texts (Cv 10), after the Buddha returned to visit his father in Kapilavatthu, his aunt and step-mother, Mahapajapati Gotami, followed him back to Vesali and eventually ordained her using the eight garu dhammas as her higher ordination. He then gave the injunction that the male monks were to ordain the female monks, which was the beginning of the bhikkhuni sangha.</p>
<blockquote>
<p>1. Now Mahā-pajāpatī the Gotamī went up to the place where the Blessed One was, and bowed down before him, and stood respectfully on one side. And, so standing, Mahā-pajāpatī the Gotamī spake thus to the Blessed One: 'What course, Lord, should I pursue towards these women of the Sākya clan?'</p>
<p>Then the Blessed One taught Mahā-pajāpatī the Gotamī and incited her, and aroused her, and gladdened her with religious discourse; and she, so taught, incited, aroused, and gladdened, bowed down before the Blessed One, and keeping him on net right hand as she passed him, she departed thence.</p>
<p>Then the Blessed One, in that connexion, delivered a religious discourse, and said to the Bhikkhus, 'I allow Bhikkhunīs, O Bhikkhus, to receive the upasampadā initiation from Bhikkhus.'</p>
<p>2. Now those Bhikkhunīs said to Mahā-pajāpatī the Gotamī: 'Neither have you received the upasampadā initiation, nor have we; for it has thus been laid down by the Blessed One: &quot;Bhikkhunīs are to be initiated by Bhikkhus.&quot;'</p>
<p>Then Mahā-pajāpatī the Gotamī went to the venerable Ānanda, and [repeated their words to him]. And the venerable Ānanda went to the Blessed One, and [repeated them to him].</p>
<p>'In that moment, Ānanda, when Mahā-pajāpatī the Gotamī took upon herself the Eight Chief Rules, that was to her as the upasampadā initiation.'</p>
<p>-- Cv 10.2 (Rhys-Davids, trans)</p>
</blockquote>
